In the largest study of its kind, an international team of researchers led by researchers at the Technical University of Munich and scientists at <a href="https://www.helmholtz-munich.de/en/newsroom/news-all/artikel/restless-legs-syndrome-genetic-discoveries-advance-treatment-and-risk-prediction" target="_blank" rel="noreferrer noopener">Helmholtz Munich</a>, a health research center in Germany, identified new genetic variants associated with restless legs syndrome.



<h2 class="wp-block-heading" id="h-harnessing-the-power-of-genetics">Harnessing the Power of Genetics</h2>



Published in the journal <a href="https://www.nature.com/articles/s41588-024-01763-1" target="_blank" rel="noreferrer noopener">Nature Genetics</a>, the study identified more than 160 genetic associations for the condition, giving researchers a better understanding of the biological pathways for restless leg syndrome. The genetic findings also point researchers to possible drug targets for treating restless leg syndrome.



While not the first genetic study into the condition by this group of researchers, it is by far the largest, and the size of the highlights sex differences revealed ten times more genetic variants associated with the condition. The researchers achieved this by using data from more than 1.5 million people. More than 90 percent of the 23andMe customers consented to participate in the research. However, the study also included data from about 25,000 people who are part of the INTERVAL Study and another 25,000 or so from the International EU_RLS-Gene consortium.



“For the first time, we achieved the ability to sufficiently assess the risk for restless leg syndrome,” said Juliane Winkelmann, Head of the Institute of Human Genetics at the Technical University of Munich, as well as the Institute of Neurogenomics at Helmholtz Munich.



Dr. Winkelmann has researched restless leg syndrome for more than 25 years. She helped lead an international team of researchers that included other scientists at Helmholz Munich, the Technical University of Munich, and the University of Cambridge.



“It’s been a long journey, but now we are empowered not only to treat but to learn how to prevent this condition,” Dr. Winkelmann said.



<h2 class="wp-block-heading" id="h-what-is-restless-leg-syndrome">What Is Restless Leg Syndrome?</h2>



Restless leg syndrome is surprisingly common, and estimates show it affects up to 10 percent of older adults. According to researchers, it also affects people of European ancestry at higher rates than other ethnicities.



As the name implies, restless leg syndrome causes uncomfortable sensations and an urge to move one’s legs. It often occurs at night and can lead to sleep disruption. Along with the discomfort and urge to move, up to 80 percent of those with restless leg syndrome also experience uncontrolled leg movement during sleep, according to <a href="https://www.ninds.nih.gov/health-information/disorders/restless-legs-syndrome" target="_blank" rel="noreferrer noopener">the National Institutes of Health</a>.



Considered a neurological condition, restless leg syndrome, also known as Willis-Ekborn disease, is caused by many different factors, including genetics and environmental factors. Women are slightly more likely to experience it than men. It sometimes appears during pregnancy but goes away after delivery.



Some research suggests that low iron levels in certain brain parts may be a factor, while other research points to dopamine, a chemical messenger in the brain that helps control body movement.



<h2 class="wp-block-heading" id="h-is-restless-leg-syndrome-genetic">Is Restless Leg Syndrome Genetic?</h2>



Studies of families and twins have shown a strong genetic component to the disorder, which led to the discovery of six genetic variants that increased the risk of developing the condition.



<div style="float: right; text-align: justified; width: 300px; background-color: #eee; padding: 15px; margin-left: 10px;"><h2>Learn More</h2>
 

 
Along with contributing to this research and a previous study of restless leg syndrome, 23andMe+ Premium includes a Restless Leg Syndrome report, Powered by 23andMe Research. The report uses a statistical model based on many genetic variants to estimate a person’s likelihood of developing restless leg syndrome. The report is part of a group of reports that focus on sleep quality, including reports on insomnia, obstructive sleep apnea, sleep movement, deep sleep and wake time. 

 Find out more about all that 23andMe offers <a href="https://www.23andme.com/compare-dna-tests/">here</a>. 
</div>



The cause of restless leg syndrome involves a complex interaction between genetic and environmental factors. However, for years, understanding the underlying biology remained largely elusive, hindering the development of effective treatment and prevention strategies.



The new research published earlier this month expands on the known genetic variants associated with restless leg syndrome, revealing more details about the genes involved, which will help those looking for more effective treatments. Some associations are on or near genes involved in changes in the formation of neuronal circuits as well as the growth and development of nerve cells, a process known as neurogenesis. Among the associations identified, the researchers also identified 13 genes associated with restless leg syndrome currently targeted by approved drugs but not for restless leg syndrome. That could offer promising avenues for repurposing medications for restless leg syndrome treatment.



In addition, the researchers used the accumulation of associated genetic variants and non-genetic factors to create a risk prediction model that performed well in estimating the likelihood of developing restless leg syndrome.



<h2 class="wp-block-heading" id="h-can-restless-legs-syndrome-impact-your-health">Can restless legs syndrome impact your health?</h2>



Symptoms from restless leg syndrome range from simply uncomfortable to truly painful, and that can vary from day to day.



The implications from the range of symptoms extend beyond how they might make one feel and can also impact one’s overall health. That’s because restless leg syndrome disrupts a person’s ability to fall and stay asleep.



Over time, this can take its toll with changes in mood, exhaustion, and difficulty concentrating. In addition, restless leg syndrome is also associated with other conditions, such as anxiety and depression. The condition is also associated with cardiovascular disease and type 2 diabetes. Because many of those with restless leg syndrome don’t realize they have it, they may try to self-medicate with alcohol or over-the-counter sleep aids, which in turn can make the condition worse.



However, some treatments and lifestyle changes could help ease those symptoms. For example, ensuring that you are getting enough iron, limiting alcohol and caffeine, and avoiding smoking can help alleviate symptoms. In addition, regular exercise, massage, and warm baths can help.

23andMe Blog

23andMe Blog Team

The Genetics of Restless Leg Syndrome

Editor&#8217;s note: For Juneteenth we&#8217;re republishing a post from earlier this year about connecting a woman and her family to the remains of a little girl buried among those of other enslaved African Americans near a historic iron furnace in Maryland. 



Agnes Jackson lives in Hagerstown, Maryland, near her four daughters and about 20 miles from the Catoctin Furnace, a historic site.&nbsp;



This long-ago shuttered iron smelter is one of the earliest industrial sites in the United States. The old iron furnace is on the edge of the Catoctin Mountain National Park, a verdant open space blanketed in forest and lined with hiking trails along the edge of the Blue Ridge Mountains.



<h2 class="wp-block-heading" id="h-an-iron-furnace">An Iron Furnace</h2>



The beauty of the place belies the brutal conditions that once made up the day-to-day lives of the free and enslaved African Americans who lived and worked there.&nbsp;



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="576" src="http://35.88.189.111/wp-content/uploads/2024/03/Photo-of-Agnes-1024x576.jpg" alt="A photo of Agnes Jackson." class="wp-image-32672" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Agnes-1024x576.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Agnes-300x169.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Agnes-768x432.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Agnes-880x495.jpg 880w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Agnes-1180x663.jpg 1180w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /><figcaption class="wp-element-caption">Agnes Jackson, as researchers explain her genetic connection to a girl buried at the historic Catoctin Furnace.</figcaption></figure>



Until recently, Agnes, who is 86, knew little of that history or her deep connection to those who lived and worked there.



Despite living so close, Agnes and her daughters visited Catoctin for the first time only about a year ago, soon after she learned about her family&#8217;s link to the site.&nbsp;



&#8220;We never knew,&#8221; Agnes said during a visit to the site last year.



With the help of the local archaeologist and president of the Catoctin Furnace Historical Society, Elizabeth Comer, and <a href="https://www.science.org/doi/10.1126/science.ade4995?adobe_mc=MCMID%3D36970045036454591841970885085615049025%7CMCORGID%3D242B6472541199F70A4C98A6%2540AdobeOrg%7CTS%3D1708709301">groundbreaking research</a> from scientists at Harvard, the Smithsonian, and 23andMe, Agnes and her family are seeing for the first time all the threads that connect them to this place and the people who toiled here.



Elizabeth, who perhaps has spent more time than anyone trying to document the legacy of the people who worked at the furnace, said adding the DNA component to this research connects this early American history to the living.



&#8220;What DNA does for the first time is connect a living, 21st-century family not just to Catoctin but to the cemetery,&#8221; she recently told Science magazine.



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="576" src="http://35.88.189.111/wp-content/uploads/2024/03/Photo-of-Elizabeth-Eadaoin-talking-to-Agnes-and-her-daughters-1024x576.jpg" alt="Photo of Agnes and her daughters talking to Éadaoin Harney, and Elizabeth Comer." class="wp-image-32671" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Elizabeth-Eadaoin-talking-to-Agnes-and-her-daughters-1024x576.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Elizabeth-Eadaoin-talking-to-Agnes-and-her-daughters-300x169.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Elizabeth-Eadaoin-talking-to-Agnes-and-her-daughters-768x432.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Elizabeth-Eadaoin-talking-to-Agnes-and-her-daughters-880x495.jpg 880w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Photo-of-Elizabeth-Eadaoin-talking-to-Agnes-and-her-daughters-1180x664.jpg 1180w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /><figcaption class="wp-element-caption">From left Éadaoin Harney, Elizabeth Comer, Agnes Green, her daughters Vicki Winston, Sharon Green, and Barbara Hart. </figcaption></figure>



<h2 class="wp-block-heading" id="h-groundbreaking-genetic-study">Groundbreaking Genetic Study</h2>



Earlier this month, Elizabeth and 23andMe scientist Éadaoin Harney visited with Agnes and three of her daughters, Sharon Green, Vicki Winston, and Barbara Hart, at a museum commemorating the Catoctin Furnace and the enslaved and free people who worked there.



Éadaoin was the lead author of a study published in the journal Science last year. The other researchers in the study included senior authors David Reich at Harvard and Doug Owsley at the Smithsonian. The researchers sequenced and studied genetic data from the remains of 27 anonymous enslaved and freed African Americans buried at the site. 



<figure class="wp-block-embed aligncenter is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio"><div class="wp-block-embed__wrapper">
<iframe loading="lazy" title="Catoctin + 23andMe" width="500" height="281" src="https://www.youtube.com/embed/FJ-wWvZVK94?feature=oembed" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
</div></figure>



The remains were uncovered decades ago during a highway construction project and buried in an unmarked burial ground. Researchers noted that the genetically related individuals were clustered into five family groups: mothers, children, and siblings.



The study leveraged 23andMe&#8217;s extensive research database to find genetic connections between those anonymous individuals and more than 41,000 relatives, although most of whom are very distantly related. The paper broke new ground by providing a technical and <a href="https://blog.23andme.com/articles/ethics-and-the-study-of-historic-dna-catoctin-furnace">ethical benchmark for future studies</a> of similar, largely forgotten burial sites. Agnes and her family were the first of the living close relatives to be informed that they share a previously unknown genetic connection to a historical individual using the first-of-its-kind approach developed by 23andMe researchers for this study.



When the paper was published in August 2023, Carter Clinton, an African American geneticist at North Carolina State University, said the research was &#8220;significant for every African American in the country.&#8221;&nbsp;



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="576" src="http://35.88.189.111/wp-content/uploads/2024/03/The-Catoctin-Furnace-1024x576.jpg" alt="A photo of the Catoctin Furnace" class="wp-image-32668" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/03/The-Catoctin-Furnace-1024x576.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2024/03/The-Catoctin-Furnace-300x169.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2024/03/The-Catoctin-Furnace-768x432.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2024/03/The-Catoctin-Furnace-880x495.jpg 880w, https://blogcms.23andme.com/wp-content/uploads/2024/03/The-Catoctin-Furnace-1180x664.jpg 1180w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /></figure>



<h2 class="wp-block-heading" id="h-the-human-connection">The Human Connection</h2>



For Agnes, it was also personal. One of those family groups that the study identified at the Catoctin site included the remains of a young girl between the ages of two and three years old. There were few artifacts with the body, just some pins, nails, and screws found with her remains. The nails and screws were likely the only surviving remnants of the coffin she was buried in, and one of the pins was perhaps used to hold back the little girl&#8217;s hair, some of the researchers suspect. The other pins were likely used to fasten a burial shroud.&nbsp;



Comparing the genetic sequence of this little girl with Agnes, Éadaoin and the team of scientists saw a large amount of shared DNA, indicating they were relatively closely related. The most likely connection is with Agnes&#8217;s great-great-grandfather, Hanson Summers. It’s possible that Hanson and the girl were half-siblings or cousins.&nbsp;



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="577" src="http://35.88.189.111/wp-content/uploads/2024/03/Agnes-and-three-of-her-daughters-1024x577.jpg" alt="A photo of Agnes, left, with her daughters, Vicki Winston, Sharon Green, and Barbara Hart." class="wp-image-32665" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/03/Agnes-and-three-of-her-daughters-1024x577.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Agnes-and-three-of-her-daughters-300x169.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Agnes-and-three-of-her-daughters-768x432.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Agnes-and-three-of-her-daughters-880x495.jpg 880w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Agnes-and-three-of-her-daughters-1180x664.jpg 1180w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /><figcaption class="wp-element-caption">Agnes, left, with her daughters, Vicki Winston, Sharon Green, and Barbara Hart.</figcaption></figure>



Often, there is family lore, stories passed down from generation to generation, but it is rare for African Americans to trace back their family history, often hitting the brick wall of slavery. Often, historical records for those enslaved ancestors are spotty. Names may never have been recorded or are only partially recorded.&nbsp;



For Agnes&#8217;s family, it was no different. She knew nothing of her family&#8217;s connection to the iron furnace. That changed a few years ago during this study when researchers from the Catoctin Furnace Historical Society, who had been attempting for years to find living descendants, had their first success. Elizabeth helped connect Agnes&#8217;s family to the furnace using paper records and historical sleuthing. The connection was through her great-great-grandfather, Hanson &#8220;Henson&#8221; Summers, who&#8217;d been enslaved at the iron furnace site in the early 19th century.&nbsp;



<h2 class="wp-block-heading" id="h-a-family-s-history-and-american-history">A Family&#8217;s History and American History</h2>



The family, of course, knew that their ancestors had been enslaved. They knew he’d worked at the Antietam Furnace that operated in Hagerstown, but they didn&#8217;t know they were linked to the Catoctin Furnace until Elizabeth connected them. 



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="577" src="http://35.88.189.111/wp-content/uploads/2024/03/Canon-balls-manufactured-at-the-furnace-1024x577.jpg" alt="Photo of cannon balls produced at the Catoctin Furnace." class="wp-image-32670" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/03/Canon-balls-manufactured-at-the-furnace-1024x577.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Canon-balls-manufactured-at-the-furnace-1180x665.jpg 1180w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Canon-balls-manufactured-at-the-furnace-300x169.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Canon-balls-manufactured-at-the-furnace-768x433.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Canon-balls-manufactured-at-the-furnace-880x496.jpg 880w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /><figcaption class="wp-element-caption">Among the many items produced at the Catoctin Furnace were cannonballs used by the Continental Army during the Revolutionary War.</figcaption></figure>



Hanson had been enslaved at Catoctin until he was in his 30s, at which point he and other members of his family were sold to the operators of the Antietam Furnace, according to the records. 



After the end of slavery, Hanson worked at an iron forge. Known for his strength and skill, he died in Hagerstown at 82 in 1899. Elizabeth&#8217;s work first found mention of Hanson in Maryland archives from 1834. His name was included on an inventory from Catoctin Furnace that included the names of enslaved African Americans. On it was a 17-year-old boy named &#8220;Henson.&#8221;&nbsp;



The Catoctin Furnace has a significant place in American history. 



<figure class="wp-block-image alignright size-medium"><img loading="lazy" decoding="async" width="300" height="168" src="http://35.88.189.111/wp-content/uploads/2024/03/Historic-Marker-for-the-Furnace-300x168.jpg" alt="A historic marker of the Catoctin Furnace" class="wp-image-32667" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/03/Historic-Marker-for-the-Furnace-300x168.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Historic-Marker-for-the-Furnace-768x431.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Historic-Marker-for-the-Furnace-1024x575.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Historic-Marker-for-the-Furnace-880x494.jpg 880w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Historic-Marker-for-the-Furnace-1180x662.jpg 1180w" sizes="auto, (max-width: 300px) 100vw, 300px" /></figure>



The first owner of the furnace was Thomas Johnson Jr. — a wealthy enslaver, the first non-colonial governor of Maryland, and a signer of the <a href="https://www.ushistory.org/declaration/related/assoc74.html">Articles of Association</a>, a precursor document to the Declaration of Independence. Iron production began in earnest in 1776. It contributed to the arming of the fledgling Continental Army — supplying 100 tons of shells for the Siege of Yorktown. While historians documented the industrial significance of the site, the history of enslaved workers there was not.&nbsp;



<h2 class="wp-block-heading" id="h-we-built-this">We Built This</h2>



Agnes and her family didn&#8217;t know their family’s contribution to that history. Agnes said that learning about her ancestors&#8217; contributions was important.



“Just to know that we actually were in history and that we made a difference,” she said. “We built this place.”&nbsp;



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="576" src="http://35.88.189.111/wp-content/uploads/2024/03/Touching-the-burial-ground-1024x576.jpg" alt="A photo of one of Agnes's daughters's hands touching the burial ground at Catoctin Furnace." class="wp-image-32669" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/03/Touching-the-burial-ground-1024x576.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Touching-the-burial-ground-300x169.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Touching-the-burial-ground-768x432.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Touching-the-burial-ground-880x495.jpg 880w, https://blogcms.23andme.com/wp-content/uploads/2024/03/Touching-the-burial-ground-1180x664.jpg 1180w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /><figcaption class="wp-element-caption">Touching the burial ground.</figcaption></figure>



That history might have remained lost had it not been a forgotten burial ground, which had been unearthed in the 1970s during a freeway construction project. Archaeologists found the remains of more than 30 individuals buried there. No records existed of who those individuals were. Over the years, the Catoctin Furnace Historical Society has worked to preserve the history of the site and the people who worked there. Only with the advent of ancient DNA technology did an effort to learn more about the DNA of individuals begin.&nbsp;



This study offered the <a href="https://blog.23andme.com/articles/historical-dna-connection-to-early-enslaved-and-free-african-americans">first genetic link</a> between enslaved or freed African Americans working at the furnace and their living relatives, including Agnes.



&#8220;It&#8217;s so exciting to see my tree… to learn more about our ancestors,&#8221; Agnes said. It&#8217;s always good to know where we came from.&#8221;

A photo of one of Agnes's daughters's hands touching the burial ground at Catoctin Furnace.

23andMe Connects Living Family to Enslaved African American from Historic Site

There’s a day for almost everything, so, of course, there’s an international <a href="https://www.dailymail.co.uk/femail/food/article-8038499/People-celebrating-International-Hate-Coriander-day.html">“I Hate Coriander Day.”</a>



Coriander, also known as cilantro, is one of the most commonly used herbs in the world, but people&#8217;s preferences for this little leafy green are one more thing that divides them.



For some, it is baffling why anyone would feel passionate loathing for an ingredient that brings a distinctive tang to their guacamole. Meanwhile, others cringe in disgust at tasting anything with what they think of as a <a href="https://en.wiktionary.org/wiki/devil%27s_herb">“devil herb.”</a>



<figure class="wp-block-image alignright"><img loading="lazy" decoding="async" width="257" height="192" src="http://35.88.189.111/wp-content/uploads/2018/06/Cilantro-Aversion.jpg" alt="An image of a cilantro leaf and the chemical compound." class="wp-image-26278"/></figure>



(23andMe customers can learn about the genetics of their <a href="https://you.23andme.com/reports/trait.cilantro_taste/">Cilantro taste preference in their trait report</a>. If you&#8217;re curious about this or other reports but not a customer, check out our <a class="waffle-rich-text-link" href="https://www.23andme.com/compare-dna-tests/">DNA Tests</a> to get a customized genetic traits report.)



<h2 class="wp-block-heading" id="h-cilantro-tastes-like-soap-it-could-be-your-genetics">Cilantro Tastes Like Soap? It Could Be Your Genetics.</h2>



As one former 23andMe blogger said in an old ode to cilantro hatred:



“For years, I believed that every Mexican restaurant my family took me to had some kind of problem with their dishwashing machine. Why else would the food always taste like soap?”



Many people have no idea that this leafy green herb can cause such repulsion, much to the chagrin of those who find it foul. For some, cilantro tastes like soap. To others, it can taste like stink bugs, dirt, or — if they’re really dramatic – anarchy, pure evil, or the plague.



<h2 class="wp-block-heading" id="h-cilantro-taste-aversion">Cilantro Taste Aversion</h2>



Like with anything that divides people, it’s helpful to understand where the other side is coming from. We at 23andMe are here to help with some science.



Several years back, 23andMe scientists<a href="https://flavourjournal.biomedcentral.com/articles/10.1186/2044-7248-1-22" target="_blank" rel="noreferrer noopener"> </a><a href="https://flavourjournal.biomedcentral.com/articles/10.1186/2044-7248-1-22">found a &#8220;genetic component to cilantro taste perception.”</a> The findings suggested that genetic variants in the olfactory receptors may contribute to some people’s distaste for cilantro.



23andMe also offers customers a Cilantro Taste Aversion Trait Report that looks at two genetic variants associated with a dislike for cilantro and can tell you if you have slightly higher or lower odds of disliking the herb.



While genetics plays a role, culture and environment do, too. Some of that may explain the differences between people of different ancestries. In the 23andMe study, 14-21 percent of people of East Asian, African, and Caucasian ancestry disliked cilantro. In contrast, only 3-to-7 percent of those who identified as South Asian, Hispanic, or Middle Eastern disliked it.



But clearly, your environment or your cultural cuisine isn’t everything. Genetics also plays a role in this love-hate relationship.



<h2 class="wp-block-heading" id="h-cilantro-amp-genetics">Cilantro &amp; Genetics</h2>



<div style="float: right; text-align: justified; width: 300px; background-color: #eee; padding: 15px; margin-left: 10px;">
Cilantro taste in 23andMe customers Cilantro soapy-taste by ancestry
<table>
<tbody>
<tr>
<td>Ashkenazi Jewish</td>
<td>14.1%</td>
</tr>
<tr>
<td>Southern European</td>
<td>13.4%</td>
</tr>
<tr>
<td>Northern European</td>
<td>12.8%</td>
</tr>
<tr>
<td>African-American</td>
<td>9.2%</td>
</tr>
<tr>
<td>Latino</td>
<td>8.7%</td>
</tr>
<tr>
<td>East Asian</td>
<td>8.4%</td>
</tr>
<tr>
<td>South Asian</td>
<td>3.9%</td>
</tr>
</tbody>
</table>
Sex differences in cilantro taste perception
<table>
<tbody>
<tr>
<td>&nbsp;</td>
<td>Female vs. Male</td>
</tr>
<tr>
<td>Tastes soapy</td>
<td align="right">57% vs. 43%</td>
</tr>
<tr>
<td>Doesn&#8217;t taste soapy</td>
<td align="right">49% vs. 51%</td>
</tr>
</tbody>
</table>
</div>



Humans have hundreds of receptors that send signals to our brains to produce what we recognize as aromas and flavors.



However, this is complex and differs from person to person. For example, the same chemical can be found in appealing and unappealing places — cheese and body odor. Conversely, the same ingredient — such as cilantro — can contain both pleasant and unpleasant chemicals. Whether stinky cheese and cilantro are delicious or disgusting depends on your perception of many different substances.



The two genetic variants used in 23andMe’s Cilantro Taste Aversion trait report are in a cluster of olfactory receptor genes. These are biological sensors that detect chemicals in the air and in food. These receptor genes are also linked to the ability to detect aldehydes, chemical compounds found in soap, which are thought to be a significant component of cilantro aroma.



<h2 class="wp-block-heading" id="h-supertasters">Supertasters</h2>



One type of aldehyde has been described as “fruity” and “green,” and another as “soapy” and “pungent.”



One of the eight genes near the variants 23andMe uses in its report codes for a receptor called OR6A2, known to detect aldehydes such as those found in cilantro. Although this finding proves that genetic variation in olfactory receptors is involved in cilantro taste perception, common genetic variants explain only a tiny part of the difference — a half percent — between 23andMe customers for this trait.



This doesn’t mean genetics can’t play a significant role in a person. Indeed, some people are <a href="https://blog.23andme.com/articles/tasty-genetics"> &#8220;supertasters&#8221;</a> or may have specific genetic variations that cause them to detect or not detect certain smells and flavors. One thing’s for sure—if you hate cilantro, you really hate cilantro!



<h2 class="wp-block-heading" id="h-learn-more">Learn More</h2>



If you aren&#8217;t already a 23andMe customer, check out your <a href="https://you.23andme.com/reports/trait.cilantro_taste/">Cilantro Taste Aversion trait report here.</a> Not yet a customer? Find out <a href="https://www.23andme.com/compare-dna-tests/?sub=ver2&amp;cabt=nao">all that 23andMe offers here</a>.

Cilantro Taste Gene – Everything You Should Know

Scientists at 23andMe, with support from The Michael J. Fox Foundation for Parkinson’s Research, have researched Parkinson&#8217;s disease and uncovered new insights into the natural history of the <a href="https://academic.oup.com/brain/advance-article/doi/10.1093/brain/awae073/7676517">LRRK2 G2019S variant</a>. The findings, tracing back thousands of years, vividly illustrate how our DNA combines history, ancestry, and health. They remind us how important knowing one is for understanding the other.



<h2 class="wp-block-heading" id="h-your-genetic-ancestry-relates-to-health">Your Genetic Ancestry Relates to Health</h2>



While some of us use 23andMe to learn more about our health and others to learn about our ancestry, your DNA isn&#8217;t just about one thing or the other. Your DNA intricately weaves together not just your health and ancestry but much more, connecting you to the long thread of human history and offering insight into the origin of diseases like Parkinson&#8217;s.&nbsp;



The history of the LRRK2 G2019S variant and its geographical distribution in disparate communities are telling.



“The fact that the LRRK2 G2019S variant is found in North African Arabs, Ashkenazi Jews, Sephardic Jews, and populations in Latin America and the Caribbean tells a story of our shared genetic roots,” said Lucy Norcliffe-Kaufmann, Ph.D., Principal Scientist with 23andMe’s Parkinson’s Disease Research program.



<h2 class="wp-block-heading" id="h-the-founder-mutation">The Founder Mutation</h2>



Studying specific genes, like LRRK2, can teach us much. The LRRK2 variant—also known as the LRRK2 G2019S founder mutation—is strongly associated with a particular form of Parkinson&#8217;s disease, which we&#8217;ll briefly detail.&nbsp;



First, let&#8217;s explain a founder mutation. A founder mutation refers to genetic variants arising from a population&#8217;s loss of genetic variation. This happens when a distinctive population emerges from a small number of people isolated by geography or culture for a considerable time.&nbsp;



The isolation of small populations can result in a higher-than-average frequency for specific genetic variants within that population.&nbsp;



For example, over generations, the geographic isolation of Finnish people led to a founder mutation that puts them at a higher risk for a kidney condition known as <a href="https://rarediseases.info.nih.gov/diseases/1500/congenital-nephrotic-syndrome-finnish-type">congenital nephrotic syndrome</a>. The isolation of French Canadians in Quebec offers another example. That isolation led to a founder mutation in the BRCA1 and BRCA2 genes that puts them at higher risk for breast and ovarian cancer.&nbsp;



Some of the most well-known founder mutations are among people with Ashkenazi Jewish ancestry. Isolated over time by culture, religion, and, in some cases, geography led to higher incidences of specific genetic variants within Ashkenazi populations. These genetic variants put them at higher genetic risk for breast and ovarian cancer.&nbsp;



But people of Ashkenazi ancestry are also more likely to have the LRRK2 G2019S founder mutation that puts them at more risk for a specific type of Parkinson&#8217;s disease.



<h2 class="wp-block-heading" id="h-lrrk2-associated-parkinson-s">LRRK2-Associated Parkinson&#8217;s</h2>



Looking specifically at LRRK2 G2019S, the variant doesn&#8217;t just convey an increased risk for Parkinson&#8217;s. People who develop the disease who have the variant also have different types of symptoms than others with Parkinson&#8217;s but who do not have the LRRK2 variant.&nbsp;



23andMe researchers <a href="https://academic.oup.com/brain/article-lookup/doi/10.1093/brain/awae073">recently published data in </a>Brain, that looks at some of those differences.&nbsp;



People with LRRK2-associated Parkinson&#8217;s disease tend to have a slower progression of the disease, with symptoms more related to motor dysfunction. People with this LRRK2 variant also have lower rates of <a href="https://www.michaeljfox.org/news/ask-md-acting-out-dreams-and-parkinsons-disease">REM sleep behavior disorder</a> or RBD, which is a common symptom of Parkinson&#8217;s, particularly in the early stages. RBD includes sleep interrupted by acting out dreams and is much more common in people with idiopathic Parkinson&#8217;s disease, or Parkinson&#8217;s, in which the cause is unknown. 



<h2 class="wp-block-heading" id="h-different-types-of-symptoms">Different Types of Symptoms</h2>



Loss of smell, another common symptom of Parkinson&#8217;s, is also less common in those with the LRRK2 variant. This is important because when we look for people with early Parkinson’s disease, we ask about loss of smell and RBD to determine whether there are early signs of neurodegeneration in the brain. We might be underestimating the risk of Parkinson’s disease in someone with the LRRK2 variant because they are less likely to have sleep and smell problems.&nbsp;



In addition, people with LRRK2-associated Parkinson&#8217;s have fewer cognitive issues and seem to be at a lower risk for developing dementia. This suggests that the LRRK2 variant leads to a slowly primarily progressive motor form of Parkinson’s disease, in which the neurodegenerative process appears to be restricted to areas of the brain that control movement. The data suggests that in LRRK2 Parkinson’s disease, the areas outside the motor control regions are spared from the neurodegenerative process, so we see fewer autonomic, cognitive, sleep, and smell issues in carriers that develop the disease.&nbsp;



The researchers point out that it’s unusual to see a dominant mutation like LRRK2 so prevalent across different communities, but that may be partly because of the later onset of LRRK2-associated Parkinson’s. Symptoms tend to show when people are in their 60s and well past reproductive years.



“This explains why the variant can be harbored in a community and flourish in subsequent generations, particularly in communities that remain isolated by persecution or geography,” Lucy said.&nbsp;



These differences beg many questions, but they also offer potential avenues of inquiry that could give researchers insights into how to treat different types of Parkinson&#8217;s disease better. The majority of Parkinson’s cases do not have a known cause, but in the case of LRRK2, because the association is known, knowing that you have the variant sooner can lead to earlier treatment and better outcomes.



To develop new therapies, scientists need to learn more about who is at risk, why, and the earliest signs of the disease.



<h2 class="wp-block-heading" id="h-the-origins-of-lrrk2-variant">The Origins of LRRK2 Variant</h2>



Beyond that, tracing where and when the LRRK2 G2019S founder mutation originated offers other opportunities to find carriers in diverse populations and build community among those people.&nbsp;



Looking at the history of the LRRK2 founder mutation also offers insight into human migration and some of the people most impacted by it. One of the novel findings of this study is the identification of “hotspots” of people from Mexico, Cuba, Puerto Rico, and Brazil who carry the LRRK2 G2019S mutation at higher rates. This is interesting because it explains the migratory history of the populations most affected by this mutation.



Scientists believe the LRRK2 founder mutation originated over 5000 years ago among the Berber people of North Africa in what is now Morocco. Rates of LRRK2 are higher within North African populations, but why are there also higher incidences of people with LRRK2 within people of Ashkenazi Ancestry?



Why is LRRK2 also found in higher frequency in North Africa and parts of Spain, Eastern Europe, Cuba, and Puerto Rico? That latter finding for a higher frequency of people in the Latin Caribbean community with higher rates of this variant is a new finding from this research by 23andMe, and it begs the question of why we see those higher rates.



The answer lies in the unique history of people of Jewish ancestry, shaped by trade routes around the Mediterranean and historical events like the Muslim Arab expansion, the Crusades, the Inquisition, and the colonization and migration into the Americas.&nbsp;



<h2 class="wp-block-heading" id="h-tracing-lrrk2">Tracing LRRK2</h2>



Scientists believe the LRRK2 founder mutation originated in the Berber populations of North Africa and then passed through the Maghrebi into the Jewish communities that arrived there, having fled the Roman invasions of Jerusalem.



The Maghrebi were mostly traders connected to other Jewish communities by religion and trade routes that crisscrossed the Mediterranean. The Berbers and the new Jewish settlers lived side by side, and many Berbers converted to Judaism, which is likely how the LRRK2 G2019S variant moved from the Berbers to the North African Jews.&nbsp;



Some of those communities eventually migrated from North Africa to mainland Europe with the Arab invasions. Around 1,500 years ago, about eight percent of people living in Spain were of Jewish descent. Within a couple of hundred years, the Jewish population split, with the Ashkenazi group settling in Germany, France, and Eastern Europe and speaking Yiddish. Meanwhile, the Iberian-Arab Jews, later known as the Sephardic Jews, moved to and from North Africa to Spain and Portugal over the next hundreds of years.&nbsp;



While different significant historical events, such as Muslim Arab expansion and later the Crusades, influenced the movement of these people, we can already see that the LRRK2 G2019S variant was present in both the Ashkenazi and Sephardic Jews. The Ashkenazi Jews went through what we call a genetic bottleneck, which reduced the population pool to a small number of founders, some of whom carried the G2019S variant. This is how the carrier rate amplified as the small surviving population recovered and expanded over subsequent generations.&nbsp;



<figure class="wp-block-image aligncenter size-full"><img loading="lazy" decoding="async" width="512" height="252" src="http://35.88.189.111/wp-content/uploads/2024/05/LRRK2-Hotspots.jpg" alt="Heat maps of different areas in Latin America, and the Caribbean where there are hotspots for LRRK2." class="wp-image-32943" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/05/LRRK2-Hotspots.jpg 512w, https://blogcms.23andme.com/wp-content/uploads/2024/05/LRRK2-Hotspots-300x148.jpg 300w" sizes="auto, (max-width: 512px) 100vw, 512px" /></figure>



<h2 class="wp-block-heading" id="h-the-new-world">The New World </h2>



By the time the Inquisitions arrived, many of what became the Sephardic Jewish community in Spain and Portugal were expelled or forced to convert to Catholicism. Their religion may have changed, but their genetics did not. Some forced converts fled to the Americas after 1492 as Spain conquered the New World. This is how the G2019S variant winds up in Latin America and Brazil.&nbsp;



Using data from 23andMe research participants who consented to participate in this research, 23andMe scientists plotted on a map where those with the LRRK2 variant trace their ancestry.&nbsp;



The maps note the fingerprints of that migration history with the highest concentrations for the mutation in people with genetic ancestry from North Africa, Eastern Europe, Puerto Rico, Cuba, and parts of South America.



“The fact that we see the LRRK2 G2019S variant signal in the Caribbean maps fits with the history of the Jewish Conquistadors who sailed with Columbus on his voyages to the New World,” said Lucy.&nbsp;



We also see strong signals in Brazil, one of the first South American countries to allow Jewish people to live and practice freely.&nbsp;



“(The finding) extends beyond the classic assumption that LRRK2 PD occurs in North African Berbers and the Ashkenazi Jews,” Lucy said. “It is an example of how mutations migrate and can spring up in new founding communities.”



<h2 class="wp-block-heading" id="h-23andme-s-ongoing-parkinson-s-research">23andMe&#8217;s Ongoing Parkinson&#8217;s Research</h2>



Understanding this history and the significance of a person&#8217;s ancestry related to the LRRK2 G2019S mutation and its link to a higher risk for Parkinson&#8217;s disease allows researchers to build awareness within these communities.&nbsp;



This, in turn, may help improve how we screen for the disease and how to build a broader community around this specific type of Parkinson&#8217;s disease.



<figure class="wp-block-image size-large"><img loading="lazy" decoding="async" width="1024" height="779" src="http://35.88.189.111/wp-content/uploads/2024/05/Mapping-LRRK2-Symptoms-to-Brain-1024x779.png" alt="Mapping of LRRK2 PD symptoms to areas of the brain." class="wp-image-32942" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/05/Mapping-LRRK2-Symptoms-to-Brain-1024x779.png 1024w, https://blogcms.23andme.com/wp-content/uploads/2024/05/Mapping-LRRK2-Symptoms-to-Brain-300x228.png 300w, https://blogcms.23andme.com/wp-content/uploads/2024/05/Mapping-LRRK2-Symptoms-to-Brain-768x584.png 768w, https://blogcms.23andme.com/wp-content/uploads/2024/05/Mapping-LRRK2-Symptoms-to-Brain-880x670.png 880w, https://blogcms.23andme.com/wp-content/uploads/2024/05/Mapping-LRRK2-Symptoms-to-Brain-1180x898.png 1180w, https://blogcms.23andme.com/wp-content/uploads/2024/05/Mapping-LRRK2-Symptoms-to-Brain.png 1899w" sizes="auto, (max-width: 1024px) 100vw, 1024px" /></figure>



The LRRK2 study, known as our Parkinson&#8217;s Impact Project, or PIP, has already produced tremendous insights into the disease. It helps scientists better understand the progression of Parkinson&#8217;s and how LRRK2 PD differs from idiopathic Parkinson&#8217;s, for which there is no known cause.&nbsp;



This study is just one of many aspects of 23andMe&#8217;s long-standing commitment to studying Parkinson&#8217;s, the second most common neurodegenerative condition behind Alzheimer&#8217;s disease.&nbsp;



23andMe researchers have studied the genetic underpinnings of Parkinson&#8217;s disease since 2009. More than 30,000 people with Parkinson&#8217;s have consented to participate in our research, and more than 196,000 people without Parkinson&#8217;s also participate in this specific research.&nbsp;



Those participants have helped 23andMe scientists and our collaborators complete work leading to more than 30 published papers, including 12 since 2020 alone. These studies have also identified almost 100 new genetic variants associated with Parkinson&#8217;s disease. It also allows 23andMe scientists and our collaborators to explore in much more detail the role these variants play in the progression of the disease.&nbsp;



The work on LRRK2 G2019S is part of that broader effort. The number of people with the LRRK2 mutation participating in 23andMe research is three times the size of the next largest LRRK2 research cohort. Some of those participating in 23andMe LRRK2 research have Parkinson&#8217;s, and others don&#8217;t.&nbsp;



As we learn more, we will share more about this study&#8217;s relevance to the disease progression and symptoms.&nbsp;



<h2 class="wp-block-heading" id="h-learn-more">Learn More</h2>



None of this work would be possible without those individuals. Those who consented to participate in 23andMe&#8217;s research included people with and without Parkinson&#8217;s disease.



Learn more about <a href="https://www.23andme.com/pd/">23andMe&#8217;s Parkinson&#8217;s disease research here</a>. 



<h2 class="wp-block-heading" id="h-the-23andme-s-parkinson-s-disease-genetic-health-risk-report">The 23andMe&#8217;s Parkinson’s Disease Genetic Health Risk Report</h2>



You can learn whether you may have an increased risk of developing Parkinson’s disease based on your genetics through the 23andMe Parkinson’s Disease Genetic Health Risk report.*



The report looks at two specific genetic variants associated with Parkinson’s disease, one in the LRRK2 gene and one in the GBA gene. This report is included in the <a href="https://www.23andme.com/dna-health-ancestry/">23andMe Health + Ancestry Service.</a>



<h2 class="wp-block-heading" id="h-note">Note</h2>



*The 23andMe PGS test uses qualitative genotyping to detect select clinically relevant variants in the genomic DNA of adults from saliva for the purpose of reporting and interpreting genetic health risks. It is not intended to diagnose any disease. Your ethnicity may affect the relevance of each report and how your genetic health risk results are interpreted. Each genetic health risk report describes if a person has variants associated with a higher risk of developing a disease, but does not describe a person’s overall risk of developing the disease. The test is not intended to tell you anything about your current state of health, or to be used to make medical decisions, including whether or not you should take a medication, how much of a medication you should take, or determine any treatment. The Parkinson’s Disease genetic health risk report is indicated for reporting of the G2019S variant in the LRRK2 gene, and the N370S variant in the GBA gene and describes if a person has variants associated with an increased risk of developing Parkinson’s disease. The variants included in this report are most common and best studied in people of European, Ashkenazi Jewish, and North African Berber descent.

The Natural History of a Genetic Variant Associated with Parkinson’s Disease

In one of the largest studies of its kind, a team of researchers led by scientists at <a href="https://www.newswise.com/articles/a-deep-dive-into-the-genetics-of-alcohol-consumption#:~:text=Sanchez%2DRoige%20explained%20that%20variants,drinking%20to%20alcohol%20use%20disorder.">UC San Diego</a> found that genetic variants known to be protective against alcohol use disorder and excessive drinking were also associated with numerous health outcomes, many having nothing to do with drinking. 



Published in <a href="https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(24)00121-X/fulltext">Lancet eBioMedicine</a>, the study included data from more than three million 23andMe customers from diverse populations who’d consented to participate in research.&nbsp;



<h2 class="wp-block-heading" id="h-metabolizing-alcohol">Metabolizing Alcohol</h2>



The work builds on the <a href="https://blog.23andme.com/articles/the-genetics-of-alcoholism">ongoing research by the team at UCSD</a>, which has previously looked at genetic variants associated with alcohol dependence and alcohol use disorder, as well as associated psychiatric traits.&nbsp;



That work has already contributed to a better understanding of the genetic underpinning of alcohol use and addiction and offers important insights into the heritability of alcoholism.&nbsp;



Those studies identified the importance of genes involved in alcohol metabolism, ADH1B and ADH1C. Some variants in those genes control the speed rate at which a person metabolizes ethanol, the intoxicating chemical in alcoholic drinks.



“And that causes many negative effects,” said <a href="https://profiles.ucsd.edu/alexandra.sanchezroige">Sandra Sanchez-Roige,</a> an associate professor at UCSD School of Medicine Department of Psychiatry and a lead author on the research.



These individuals may almost immediately feel nausea or a headache, for instance.



“These variants are primarily associated with how much someone may consume alcohol,” Sanchez-Roige said. “And they also tend to prevent alcohol use disorder because these variants are primarily associated with the quantity of alcohol someone may drink.”



<h2 class="wp-block-heading" id="h-surprising-associations">Surprising Associations</h2>



In this study, the researchers found that the variants in those genes that protect against heavy drinking also protect against a wide range of health outcomes. Some of those include metabolic diseases, such as obesity and high cholesterol, cardiovascular conditions, and some sleep and psychiatric disorders. 



However, and maybe counterintuitively, they were also associated with an increased risk of unexpected health conditions, such as allergies, eye health, and migraines. While some of these associations may not be causal, they offer new avenues for researchers to investigate.&nbsp;



Read the full study <a href="https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(24)00121-X/fulltext">here</a>.

Genetic Variants Protective Against Alcoholism May Impact Other Health Outcomes

In time for Colon Cancer Awareness Month, 23andMe launched its <a href="https://www.23andme.com/genetic-insights-into-colorectal-cancer-black-community/">Genetic Insights into Colorectal Cancer in the Black Community</a> study this week that we hope will help improve the performance of genetic report models that could help alert those with a higher likelihood of developing colorectal cancer.



<h2 class="wp-block-heading" id="h-awareness">Awareness</h2>



March is Colon Cancer Awareness Month. Did you know that Colorectal cancer is one of the most common forms of cancer? It is also one of the leading cancer-related causes of death in the United States, according to the US Centers for Disease Control and Prevention. Its impact on people of color is particularly pernicious because they tend to be diagnosed in later stages of cancer and often receive lower-quality care. That plays a significant role in why 



Black and African American individuals are about 20 percent more likely to develop colorectal cancer and about 40 percent more likely to die from it, <a href="https://www.cancer.org/cancer/latest-news/colorectal-cancer-rates-higher-in-african-americans-rising-in-younger-people.html#:~:text=Risk%20is%20higher%20in%20African%20Americans&amp;text=African%20Americans%20are%20about%2020,it%20than%20most%20other%20groups.">according to the American Cancer Society</a>.



<figure class="wp-block-image alignright size-medium"><img loading="lazy" decoding="async" width="300" height="252" src="http://35.88.189.111/wp-content/uploads/2024/02/Colorectal-Cancer-Image-300x252.png" alt="A graphic for the Colorectal Cancer Study" class="wp-image-32571" srcset="https://blogcms.23andme.com/wp-content/uploads/2024/02/Colorectal-Cancer-Image-300x252.png 300w, https://blogcms.23andme.com/wp-content/uploads/2024/02/Colorectal-Cancer-Image.png 596w" sizes="auto, (max-width: 300px) 100vw, 300px" /></figure>



Early detection makes treatment much more likely to succeed. This is why regular screening—through colonoscopy or stool-based tests—is so important. Knowing your genetic likelihood of developing the condition can raise awareness and motivation to take these vital screening steps.  



<h2 class="wp-block-heading" id="h-predictive-models">Predictive Models</h2>



Polygenic scores are a relatively new but powerful way to understand a person&#8217;s genetic likelihood for a condition. They combine the impact of hundreds or thousands of genetic variants to estimate a person&#8217;s chances. Individually, each of these variants only has a small effect on a person’s genetic likelihood, but that impact can grow when many variants are considered together. 



But the performance of these models — which rely on extensive genetic studies — tend to perform poorly for Black and African Americans, in part because of the lack of genetic research that includes data from non-European participants.



23andMe wants to improve how its polygenic score for colorectal cancer performs for Black and African American individuals and raise awareness about this form of cancer. That is the aim of this newly launched study.



<h2 class="wp-block-heading" id="h-what-is-colorectal-cancer">What is Colorectal Cancer?</h2>



Cancer occurs when abnormal cells divide and grow out of control. Colorectal cancer occurs in the colon or rectum, which are sections of the large intestine. This type of cancer usually starts as a growth called a polyp.&nbsp;



Most polyps are not cancerous, but some can turn cancerous over time. Left untreated, these cancer cells can spread beyond the colon or rectum through the blood and into the lymphatic system.&nbsp;



Like many forms of cancers, a complex mix of genetics, environment, aging, family history, and lifestyle influence whether someone develops colorectal cancer.&nbsp;



<h2 class="wp-block-heading" id="h-genes-and-environment">Genes and Environment</h2>



In a few types of colorectal cancer, such as <a href="https://www.cdc.gov/genomics/disease/colorectal_cancer/lynch.htm">Lynch syndrome</a>, <a href="https://rarediseases.info.nih.gov/diseases/6408/familial-adenomatous-polyposis">familial adenomatous polyposis (FAP)</a>, and <a href="https://blog.23andme.com/articles/23andmes-new-mutyh-report">MUTYH-associated polyposis</a>, genetics plays an outsized role. But diets that are low in fiber and fresh fruits and vegetables and high in fat and red and processed meats contribute to a higher risk for colorectal cancer, as does a lack of exercise, according to the Centers for Disease Control and Prevention. Things like eating a healthy diet, reducing alcohol consumption, not smoking, and maintaining a healthy weight can help lower one’s risk for the disease.



Current guidelines suggest starting regular screening for colorectal cancer at the age of 45 years. Still, certain risk factors, like a personal or family history of colorectal cancer or symptoms related to the disease, may call for earlier screening.&nbsp;



Although the majority of colorectal cancers are diagnosed in people over the age of 50 and the overall rate of colorectal cancers has declined in the last few decades, a <a href="https://acsjournals.onlinelibrary.wiley.com/doi/full/10.3322/caac.21772">recent study</a> by scientists with the American Cancer Society indicated that rates for those under the age of 55 have gone up. Colorectal cancer is now the leading cause of cancer death for men under 50.&nbsp;



Recognizing these trends and the disproportionate impact of colorectal cancer in the Black community, 23andMe scientists are recruiting Black and African Americans in the United States who have been diagnosed with colorectal cancer and are willing to participate in our research.&nbsp;



<h2 class="wp-block-heading" id="h-23andme-s-genetic-insights-into-colorectal-cancer-in-the-black-community-study">23andMe’s Genetic Insights into Colorectal Cancer in the Black Community Study</h2>



23andMe’s mission is to help all people access, understand, and benefit from the human genome. Several recent 23andMe initiatives have focused on conditions that affect many individuals but disproportionately affect individuals in the Black and African American communities. 



In 2022, we launched the Sickle Cell Carrier Status Awareness Program to help improve access to important information about sickle cell traits and diseases. That year, we also launched the Representation in Sarcoidosis Research Study, studying a rare inflammatory disease that affects the Black community at double the rate of individuals with European ancestry. We hope that with better representation, our products and research will benefit more people, especially when health inequities exist. One such condition is colorectal cancer.



<h2 class="wp-block-heading" id="h-a-new-study">A New Study</h2>



The newly launched <a href="https://www.23andme.com/genetic-insights-into-colorectal-cancer-black-community/">Genetic Insights into Colorectal Cancer in the Black Community</a> study will recruit Black and African American individuals in the United States who have been diagnosed with the disease. By increasing the amount of data on individuals from this community with colorectal cancer, we hope to be able to improve the polygenic score. This will strengthen our ability to inform Black and African Americans about how their genetics impact their chance of developing this form of cancer.&nbsp;



As part of this effort, 23andMe will reach out to individuals new to 23andMe. We will also connect with those currently participating in other research projects focused on the Black and African American community. The goal is to recruit Black and African American individuals who are 18 years or older, live in the United States, and have been diagnosed with colorectal cancer. If you would like additional information about how to participate in this research, you can learn more <a href="https://www.23andme.com/genetic-insights-into-colorectal-cancer-black-community/">here</a>.



If you have questions or want to contact us, email crc-study@23andme.com.

Studying Colorectal Cancer Within the Black Community

Editor&#8217;s Note: We first published this post on the heels of our collaboration with the University of California San Diego researchers. It offers some stark reminders that loneliness has a cost not just on our mental health but our physical health as well. A new report by the Centers for Disease Control reminded us of the growing number of people alone in the United States. It also reminded us of how serious a problem loneliness is for our health, as detrimental to our health as smoking. In light of that report and others looking at the rise in mental health issues among adults, we wanted to resurface this post from 2020.



Humans are social animals. We thrive through contact with other people, and the importance of that connection can be seen by what happens in its absence.



<figure class="wp-block-image aligncenter"><img loading="lazy" decoding="async" width="1254" height="836" src="https://blog-api.23andme.com/wp-content/uploads/2020/01/iStock-1051207682.jpg" alt="Loneliness has an impact on health." class="wp-image-27918" srcset="https://blogcms.23andme.com/wp-content/uploads/2020/01/iStock-1051207682.jpg 1254w, https://blogcms.23andme.com/wp-content/uploads/2020/01/iStock-1051207682-300x200.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2020/01/iStock-1051207682-768x512.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2020/01/iStock-1051207682-1024x683.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2020/01/iStock-1051207682-880x587.jpg 880w, https://blogcms.23andme.com/wp-content/uploads/2020/01/iStock-1051207682-1180x787.jpg 1180w" sizes="auto, (max-width: 1254px) 100vw, 1254px" /></figure>



Several studies have shown the damaging impact loneliness has on human health. The adverse health effects of loneliness rival that of smoking and obesity, according to <a href="https://www.tandfonline.com/doi/full/10.1080/13607863.2019.1699022">recent studies done by scientists at UC San Diego</a>.







<h2 class="wp-block-heading" id="h-loneliness-a-growing-problem">Loneliness, A Growing Problem</h2>



Growing isolation and loneliness, particularly among the elderly, have prompted public health responses. Two years ago, the United Kingdom created the first national strategy to deal with the <a href="https://www.gov.uk/government/news/pm-launches-governments-first-loneliness-strategy">health consequences of isolation</a>. The National Academies of Sciences have begun to study the problem in the United States.&nbsp;



But beyond trying to combat social isolation, scientists are also researching for possible genetic predispositions toward loneliness. They also look at where those associations might overlap with risks for specific health outcomes.&nbsp;



<h2 class="wp-block-heading" id="h-genetics-also-plays-a-role">Genetics Also Plays a Role</h2>



Two recently completed studies offer compelling evidence of a genetic predisposition toward loneliness. Both studies, which included data from 23andMe and the UK Biobank, found shared genetic associations between loneliness and other conditions like cardiovascular disease, as well as psychiatric and metabolic disorders.



­­One study, led by researchers at the University of California at San Diego, found a clear association between loneliness and coronary artery disease, particularly among women. The study, published in <a href="https://academic.oup.com/hmg/article/28/22/3853/5568316">Human Molecular Genetics</a>, used data from more than half a million individuals. The researchers found 19 variants associated with a predisposition toward loneliness. Those variants were also associated with cardiovascular disease, as well as some psychiatric and metabolic disorders. Associations between major depressive disorder, loneliness, and heart disease have been described in <a href="https://www.sciencedirect.com/science/article/abs/pii/S104727971200292X">previous studies.&nbsp;</a> However, this study found that the associations are partly explained by genetics.



In another Vanderbilt University Medical Center study, researchers used electronic medical records and data from 23andMe, the UK Biobank, and others. That study looked at the connections between loneliness, major depressive disorder, and coronary artery disease. That study found that individuals with genetic risk for loneliness and major depressive disorder were more likely to have clinical diagnoses for coronary artery disease. This association was stronger in women than men, and the effect was specific to loneliness.



The studies come amid <a href="https://www.nia.nih.gov/news/social-isolation-loneliness-older-people-pose-health-risks">increased attention</a> to the genuine public health consequences of loneliness, particularly among older people. The researchers suggest that understanding conditions associated with loneliness could help develop ways to <a href="https://www.bostonglobe.com/metro/2020/01/20/researchers-health-officials-call-for-unified-approach-loneliness-and-social-isolation/0Jqne5IjuDL1f9fg84xJBL/story.html">address the issue</a>.



<h2 class="wp-block-heading" id="h-find-out-more">Find Out More</h2>



23andMe does not have a report on loneliness, but 23andMe+ members can learn about conditions associated with loneliness, such as their genetic predisposition toward <a href="https://you.23andme.com/reports/prs.depression/">Depression</a> and <a href="https://you.23andme.com/reports/prs.anxiety/">Anxiety</a>.



Current 23andMe Health + Ancestry Service customers on the current genotyping chip can receive this report and 35+ other reports by joining 23andMe+ from within their accounts.



 Not a 23andMe+ customer yet?<a href="https://www.23andme.com/compare-dna-tests/" target="_blank" rel="noreferrer noopener"> Learn more about what 23andMe has to offer here</a>.

The Genetics of Loneliness and its Impact on Health

This week, researchers with the National Institutes of Health, in collaboration with 23andMe and about a dozen other groups, published the largest to-date genetic study of Parkinson&#8217;s disease. Notably, it is the first large-scale genetics study of Parkinson’s disease to include data from individuals from multiple ancestral populations.



Published in the journal <a href="https://www.nature.com/articles/s41588-023-01584-8.epdf?sharing_token=_D_bR6RYhWNv-TYITSaVttRgN0jAjWel9jnR3ZoTv0MXLm2Fcn84JM_K3Fp4sgRswhuaAdlB2YPeuqpzsoI4MNKvJ3ljhWd2AOqIu5CRZBmOYMtU0l3QuUcQvSvB9lDR9R0VTfDpb2CfE5JsA2S-EJ002gfivBBL_MR3GeWsgps%3D">Nature Genetics</a>, the study identified a dozen genetic loci not previously known to be associated with Parkinson&#8217;s. In addition, it confirmed 66 other known loci associated with this incurable neurodegenerative disease. It also found that some variants were associated with risk across all the populations studied.



<h2 class="wp-block-heading" id="h-the-importance-of-diversity-in-research">The Importance of Diversity in Research</h2>



This study is a reminder of the need to include more diverse populations in research, and it also highlights the potential for 23andMe to do just that. The study identified four novel gene regions associated with Parkinson&#8217;s that have different effects on different populations — in this case, people of European, East Asian, Latin American, and African ancestry.&nbsp;



However, even though this was a multi-ancestry study, there was far more data from people of European ancestry. In addition, the smaller numbers of people from non-European populations in the study meant that some of the ancestry-specific findings failed to reach statistical significance. According to the researchers, this highlights the need for more data from non-European populations to fully power this kind of research.



By including diverse populations in research, it ensures that scientists can identify population-specific genetic variations that may play a role in a disease like Parkinson&#8217;s. There is currently no other study cohort with the scale and diversity of 23andMe, which has millions of participants from diverse backgrounds who are both engaged and consented to participate in a wide variety of genetic research. However, even with the diversity of its dataset, 23andMe continues to focus on encouraging more people of non-European ancestry to participate not just in our research but the research of our collaborators.



<h2 class="wp-block-heading" id="h-23andme-parkinson-s-research">23andMe Parkinson&#8217;s Research</h2>



The study is one of many different projects 23andMe has engaged in since launching its Parkinson’s disease research program in 2009.&nbsp;



Just this week, in another collaboration between 23andMe and the NIH, researchers <a href="https://www.nature.com/articles/s41531-023-00608-8#Sec5">published a study</a> analyzing about 1,000 rare variants previously associated with Parkinson’s disease. Published in the journal <a href="https://www.nature.com/articles/s41531-023-00608-8#Sec5">Nature</a>, the paper included data from more than three million people that included about 30,000 individuals with Parkinson’s. The study was noteworthy not so much for identifying rare variants but for determining that many of these variants previously identified as associated with the disease may not in fact play a role in Parkinson’s afterall.  The study did however confirm the strong association between variants in the LRR2 and GBA1 genes and Parkinson’s.



23andMe scientists study many conditions and traits, but research into Parkinson&#8217;s disease is particularly important because of our long-term commitment to studying this condition, which affects <a href="https://www.parkinson.org/understanding-parkinsons/statistics">about a million people in the United States alone</a>.&nbsp;



Parkinson&#8217;s is the second most common neurodegenerative condition behind Alzheimer&#8217;s disease. Parkinson&#8217;s disease leads to a loss of nerve cells in the part of the brain that controls movement. As a result, there are a range of symptoms among those with the condition, and it also progresses differently within people. Symptoms include motor problems, such as tremors, stiffness of the muscles, and slow movements, as well as non-motor symptoms, such as problems with low blood pressure on standing, constipation, or sleep disturbances.



Our Parkinson&#8217;s disease research was one of the first disease-specific “deep dive” research projects 23andMe undertook, and it offered a model for other disease research. In the last 14 years, our Parkinson&#8217;s research efforts have reached several milestones, and that wouldn&#8217;t have been possible without our research participants or the vital assistance of our collaborators at <a href="https://www.michaeljfox.org/">The Michael J. Fox Foundation</a>.&nbsp;



We currently have more than 30,000 people with Parkinson&#8217;s disease who have consented to participate in our Parkinson&#8217;s research, and another 500,000 people without Parkinson&#8217;s disease who are also participating in our research efforts. Those participants have helped 23andMe scientists and our collaborators complete work leading to 30 published papers, including ten since 2020 alone. These studies have also identified almost 100 new genetic variants associated with Parkinson&#8217;s disease.&nbsp;



<h2 class="wp-block-heading" id="h-learning-from-lrrk2-nbsp">Learning from LRRK2&nbsp;</h2>



23andMe researchers are currently studying non-genetic traits that may help in diagnosing Parkinson&#8217;s disease earlier, as well as identifying <a href="https://www.biorxiv.org/content/10.1101/604033v1">putative causal risk factors</a> that influence the age of onset of the illness.&nbsp;



Our scientists are also learning more about how to characterize different types of Parkinson&#8217;s; for example, we are currently studying the LRRK2 G2019S founder mutation, which is the most common cause of “genetic” Parkinson&#8217;s. Our LRRK2 cohort is three times the size of the next largest research cohort of people with this condition. Known as the Parkinson&#8217;s Impact Project, or PIP, our researchers are learning a lot from this study.&nbsp;



For example, people with this LRRK2 variant tend to see a slower disease progression with fewer non-motor symptoms. They&#8217;re also much more likely to be of Ashkenazi Jewish descent, which relates to the history of the LRRK2 G2019S founder mutation history. It is thought to have originated from a Berber founder from North Africa more than 5,000 years ago, and later flowed into the Jewish community that eventually migrated into central Europe.&nbsp;



This study also highlights another aspect of our research. Differences in the symptoms suggest that different map areas of the brain may be less affected in LRRK2 Parkinson&#8217;s disease. This will help researchers distinguish the various subtypes of Parkinson&#8217;s disease.



For instance, individuals with the LRRK2 variant have lower rates of <a href="https://www.michaeljfox.org/news/ask-md-acting-out-dreams-and-parkinsons-disease">REM sleep behavior disorder</a>, or RBD. This symptom includes acting out of dreams during sleep. RBD is much more common in people with idiopathic Parkinson&#8217;s disease, or Parkinson&#8217;s that is caused by some unknown cause rather than by genetics. Loss of smell is also a symptom of Parkinson&#8217;s disease, but people with LRRK2 G2019S have lower rates of loss of smell. In addition, people with LRRK2-associated Parkinson&#8217;s have fewer cognition issues.&nbsp;&nbsp;



Data like this helps inform scientists about the disease and its progression, and can inform the prognosis. 23andMe scientists are working on ways to better identify people at risk of Parkinson&#8217;s and better understand how the disease may manifest and progress in those individuals.



<h2 class="wp-block-heading" id="h-ongoing-research">Ongoing Research</h2>



<a href="https://www.23andme.com/pd/">23andMe&#8217;s Parkinson&#8217;s disease research program</a> is unique in that it allows for continued engagement with participants. Scientists are better able to track changes and understand the progression of Parkinson&#8217;s. Having people who are engaged in this research over time also allows our scientists to nimbly add new dimensions to their investigations into this disease.&nbsp;



For example, one of our postdoctoral fellows, Keaton Stagaman, recently completed a small-scale pilot study in collaboration with The Michael J. Fox Foundation, looking at the <a href="https://blog.23andme.com/articles/parkinsons-disease-and-the-microbiome">gut and oral microbiomes of people with Parkinson&#8217;s</a>. It turned out to be the largest single study to test the relationship between the oral and gut microbiomes in Parkinson&#8217;s disease.&nbsp;



Another common symptom of Parkinson&#8217;s is intestinal problems, such as constipation. Over the last few years, much focus has been on the <a href="https://www.nccih.nih.gov/news/events/4-fast-facts-about-the-gutbrain-connection">gut-brain connection</a> and its relationship with disease. Our researchers wanted to understand whether the gut microbiome might play a vital role in the pathological onset of Parkinson&#8217;s disease. Our researchers are still digging through this data and plan to follow up with a much larger study later this year, including healthy controls.



We will eventually publish our research findings on this study and others, and share that information with our research participants. Finding better early-detection methods may be critical in modifying the impact of this neurodegenerative disease. Earlier intervention could help prevent the loss of neurons and stave off the worsening of symptoms, for instance. Understanding how Parkinson&#8217;s disease manifests and progresses among different people is also important.



None of this work would be possible without those individuals — both with Parkinson’s disease and those who do not have it — who’ve consented to participate in 23andMe research.



 Learn more about <a href="https://www.23andme.com/pd/">23andMe&#8217;s Parkinson&#8217;s disease research here</a>.

Large Study on Parkinson’s Disease Includes Understudied Populations

Your partner’s sleeping patterns often influence your own, whether you like it or not, <a href="https://www.nature.com/articles/s42003-023-05521-7.epdf?sharing_token=Sfu-Tt6qN6blH0kfaZfepdRgN0jAjWel9jnR3ZoTv0P-7SY3VDosErXW6Rhl-_I8fBRo2ZauE5Kr2RBMtp7mJyeHttuHukCcu3i6bSLAmolisBRZyk1jKpVxwlmFdmAbkRiIXpKlYA3lWVUY12W8u5Hp6gt9u88x47ZRUNlX5Xk%3D">a new study</a> has found.



Using data from more than 47,000 couples who are part of the <a href="https://www.ukbiobank.ac.uk/learn-more-about-uk-biobank">UK Biobank</a> and then replicated using data from 127,000 couples who consented to participate in <a href="https://research.23andme.com/publications/#publications">23andMe research</a>, scientists from the University of Bristol found that couples were correlated in numerous aspects of sleep such as how long the sleep, whether they wake up early or go to bed late and even how restless they are in the night.&nbsp;



Not only this, but the research used genetic data to show that these correlations were likely to be causal, meaning that partners were influencing each other’s sleep patterns.&nbsp;



The study found that people who slept for longer tended to have partners who also had a longer night’s sleep, and that bedtime and wake-up times were aligned between couples. However, couples differed based on their “chronotype” — their morning or evening preference – meaning if one was a morning person, the other tended to be a night owl. The researchers also noted that those with insomnia tended to be more likely to report snoring by their partner.&nbsp;



There is a lot packed into the study. Some of it touches on what is called assortative mating — the notion that we’re more likely to partner up with people with similar traits. But more importantly, it also reveals that couples who are different in their sleep preferences and traits could, over time, adopt the sleep patterns of their partner. The study suggests that in the long term, there’s a convergence among couples in how long they sleep.&nbsp;



“This highlights the importance of considering both partners in sleep health interventions,” said <a href="https://www.bristol.ac.uk/people/person/Rebecca-Richmond-9acc2c80-6921-4ce6-93be-43766b1ac185/">Rebecca C Richmond, Ph.D</a>., lead author of the study and a senior research fellow in Molecular Epidemiology at the University of Bristol.&nbsp;



The study used an impressive range of data on sleep, not just based on questionnaire measures but also genetic data and movement data from wearable devices. The study is also significant for its size. Sleep studies involving couples tend to include just a few hundred couples, whereas this involves two separate research cohorts with tens of thousands of individuals. 



 Read the complete study in the journal <a href="https://www.nature.com/articles/s42003-023-05521-7.epdf?sharing_token=Sfu-Tt6qN6blH0kfaZfepdRgN0jAjWel9jnR3ZoTv0P-7SY3VDosErXW6Rhl-_I8fBRo2ZauE5Kr2RBMtp7mJyeHttuHukCcu3i6bSLAmolisBRZyk1jKpVxwlmFdmAbkRiIXpKlYA3lWVUY12W8u5Hp6gt9u88x47ZRUNlX5Xk%3D">Communications Biology</a>.

Research — Page 6