After reading a recent <a href="https://www.slate.com/articles/health_and_science/medical_examiner/2015/08/misophonia_research_disorder_of_irritation_by_chewing_lip_smacking_sniffing.single.html">Slate piece</a>, we thought it might be worth taking one more bite at <a href="http://www.misophonia-uk.org/">Misophonia</a>.<img loading="lazy" decoding="async" class="alignright size-thumbnail wp-image-2937" src="https://blog-api.23andme.com/wp-content/uploads/2009/02/mouth-150x150.jpg" alt="mouth" width="150" height="150" />


It’s one of those conditions that you might not know is a condition, even if you have it.
<a href="https://www.23andme.com/topics/traits/misophonia/">Misophonia</a> – from the Greek word meaning hatred of sound – is characterized by feelings of rage triggered by other people chewing, sipping or chomping on their food. It’s more than just not liking bad manners at the table, but a real visceral reaction to that sound or other kinds of sounds such as sniffing, lip-smacking and even other people breathing.


Many with the condition have the same kind of surprised reaction that writer Megan Cartwright described in her Slate article. 
 

“Other people have this?! “ she asked.
She thought it was just her.
No other people have it, but often just think that it&#8217;s just them. Although Cartwright looks at a few recent small studies a little skeptically, 23andMe recently conducted an internal study looking at more than 90,000 customers who have consented to research and found that about 20 percent reported that they were “filled with rage” by the sound of others eating.


The percentage found in 23andMe’s study was similar to the numbers found in <a href="https://www.ncbi.nlm.nih.gov/pubmed/24752915">a study</a> cited by Cartwright that was done last year by psychologists at the University of South Florida. That work also found that the condition appeared to be associated with psychiatric conditions such as anxiety, depression and obsessive compulsive disorder. But other researchers said characterizing the condition, as a psychiatric disorder is a mistake.
She interviewed Dutch researcher Pawel Jastreboff, who with his wife and co-researcher, Margaret Jastreboff, first came up with the term misophonia. Pawel suggests that the condition has more to do with learned behavior by an individual with an existing <a href="https://www.ncbi.nlm.nih.gov/pubmed/25726280">sensitivity to sounds</a>.
23andMe’s research, which focused on people of European ancestry, identified a specific genetic variant, , associated with misophonia that is near the gene <a href="http://www.genecards.org/cgi-bin/carddisp.pl?gene=TENM2">TENM2</a>, which plays a role in brain development.

23andMe Blog

23andMe Blog Team

Chew on This

Consider the cow, and this humble herbivore’s contribution to the human story.<img loading="lazy" decoding="async" src="https://blog-api.23andme.com/wp-content/uploads/2015/06/dairy-cow-300x200.jpg" alt="dairy cow" class="alignright size-medium wp-image-22620" width="300" height="200" srcset="https://blogcms.23andme.com/wp-content/uploads/2015/06/dairy-cow-300x200.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2015/06/dairy-cow-768x511.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2015/06/dairy-cow.jpg 849w" sizes="auto, (max-width: 300px) 100vw, 300px" />


We’re not just talking burgers and ice cream, archeological evidence suggests that cows were likely first domesticated from aurochs (extinct wild oxen) as long as 11,000 years ago when farmers used their milk to <a href="https://www.npr.org/sections/thesalt/2012/12/27/168144785/an-evolutionary-whodunit-how-did-humans-develop-lactose-tolerance" target="_blank" rel="noopener noreferrer">make cheese</a> and yogurt.
Nutrient-rich with plenty of vitamin D for the sun-starved in Northern Europe, milk was a kind of superfood of the Bronze Age.
But <a href="https://www.nature.com/news/dna-data-explosion-lights-up-the-bronze-age-1.17723" target="_blank" rel="noopener noreferrer">new research</a> suggests that it took a long time before Europeans could actually benefit from this potent potable.
Looking at DNA samples from the remains for more than 100 individuals who lived in Eurasia from 3,000 to 5,000 years ago, researchers in Norway found that it took a surprisingly long time before Europeans could tolerate milk.
The study looked at much more than whether those early Europeans could tolerate dairy, and focused more broadly on a wide variety of physical and physiological traits including hair thickness, height and skin color.
But the DNA samples indicate that those early Europeans were mostly lactose intolerant, suggesting that even though they had domesticated cows at the time they were unable to digest raw milk as adults. The exception appears to be among the Yamnaya, a group of people who migrated into Northern Europe from an area near the Altai Mountains in what is now central Russia. Researchers speculate that natural selection favored this trait, giving those with it a rich source of nutrition that could sustained them during times of famine when harvests failed. 
 
<img loading="lazy" decoding="async" src="https://blog-api.23andme.com/wp-content/uploads/2015/06/milk-287x300.jpg" alt="Glass of milk isolated on white. Vector illustration" class="alignright size-medium wp-image-22621" width="287" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2015/06/milk-287x300.jpg 287w, https://blogcms.23andme.com/wp-content/uploads/2015/06/milk-768x802.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2015/06/milk-980x1024.jpg 980w, https://blogcms.23andme.com/wp-content/uploads/2015/06/milk-843x880.jpg 843w, https://blogcms.23andme.com/wp-content/uploads/2015/06/milk-1130x1180.jpg 1130w" sizes="auto, (max-width: 287px) 100vw, 287px" />

<h5>
Intolerant, even today 
</h5>

Most people are actually lactose intolerant as adults. Only about <a href="https://www.sciencedirect.com/science/article/pii/S0958694611002536" target="_blank" rel="noopener noreferrer">35 percent of people worldwide</a> can digest lactose beyond the age of about seven or eight.
The numbers tell a deeper story when demographically divided. While the majority of people of European ancestry <a href="https://www.nature.com/news/archaeology-the-milk-revolution-1.13471" target="_blank" rel="noopener noreferrer">can tolerate milk</a> into adulthood, only a small minority of people of Asian ancestry can. Among 23andMe customers who consented to research only about 16 percent of those of European ancestry reported that they were <a href="https://www.23andme.com/topics/wellness/lactose-intolerance/">lactose intolerant</a> compared to about 85 percent of people of Asian ancestry.

<h5>
So what gives? 
</h5>

There are a number of <a href="https://www.npr.org/sections/thesalt/2012/12/27/168144785/an-evolutionary-whodunit-how-did-humans-develop-lactose-tolerance" target="_blank" rel="noopener noreferrer">theories</a> about why there are differences among people of different ancestry, and a recent study of ancient Northern European DNA suggests the ability to digest dairy is a relatively new phenomena.
Drinking milk is a problem for most adults. It contains high amounts of a sugar named lactose. As children, we all produce lactase, an enzyme that allows us to break up lactose in our mother&#8217;s milk. As we grow older lactase levels go down, making it harder for adults to breakdown the lactose sugars and causing gastrointestinal &#8220;discomfort.&#8221;
In populations with domesticated cattle, however, there may have been an evolutionary incentive to being able to drink milk as adults and several populations – including populations in Northern Europe – developed genetic variants that enabled adults to continue to breakdown lactose into adulthood. This genetic variant offered a likely evolutionary advantage because milk is nutrient rich, plentiful, and cleaner than many sources of water. In times of famine it offered an alternative source of food for those who could tolerate it.


In the book 10,000 Year Explosion: How Civilization Accelerated Human Evolution, anthropologists Gregory Cochran and Henry Harpending called humans with this variant “<a href="https://westhunt.wordpress.com/2012/10/23/mampires/" target="_blank" rel="noopener noreferrer">mampires</a>,” because it allowed people to feed on the milk of other animals. It’s a clever term, but maybe with a little darker connotations than necessary. As the anthropologist <a href="http://johnhawks.net/weblog/reviews/accel/question-on-selection-and-lactase-2014.html" target="_blank" rel="noopener noreferrer">John Hawkes noted</a> in his blog, milk from domesticated animals is a much more efficient use of farm animals than raising them for meat. In places in Europe, Arabia and in parts of Africa where cold or arid climates made consistent yields from farming grain difficult, milk was a good alternative source of nutrition.

23andMoo

They’ve been friends since the first grade, so Rhett McLaughlin and Link Neal, YouTube stars with their own daily show, decided to see if there might be some deeper explanation for their tight bond.
On a recent episode of their popular show <a href="https://www.youtube.com/user/rhettandlink2" target="_blank" rel="noopener noreferrer">“Good Mythical Morning”</a> the two looked at their 23andMe results and then compared traits like earwax, Neanderthal percentages and whether they got a taste of soap when they grazed on <a href="https://blog.23andme.com/articles/cilantro-love-hate-genetic-trait" target="_blank" rel="noopener noreferrer">cilantro</a>.
With the kind of friendly and funny back-and-forth banter that has made many of their videos go viral, the two used their results as a way to illustrate a recent scientific finding showing that friends tend to be more alike genetically than strangers. The study by researchers at Yale and UC San Diego was published last year in the <a href="https://www.pnas.org/content/early/2014/07/10/1400825111" target="_blank" rel="noopener noreferrer">Proceedings of the National Academy of Sciences</a>, and looked at 2,000 individuals. The scientists found that friends shared about 1 percent of their DNA – equivalent to what fourth cousins would share – versus strangers who shared very little.
The study is one of several now that have looked at how shared genetics may help people bond.
23andMe researchers also looked at this phenomenon but focused specifically on <a href="https://blog.23andme.com/23andme-research/23andme-couples-correlated/" target="_blank" rel="noopener noreferrer">couples</a> with children. Our researchers found that, contrary to what some believe, opposites don’t in fact attract. The work just added to several studies done over the years showing that people tended to bond with those with whom they are more alike than those with whom they are more different.
Whether you are into the science or not, you should check out <a href="https://www.youtube.com/user/rhettandlink2/featured" target="_blank" rel="noopener noreferrer">Rhett &amp; Link&#8217;s show</a>. It&#8217;s a lot of fun.
<iframe loading="lazy" src="https://www.youtube.com/embed/Zdw4ozDD2XU" width="640" height="360" frameborder="0" allowfullscreen="allowfullscreen"></iframe>

Good Morning Friend

Along with having some very talented scientists and engineers on staff, 23andMe is lucky to have some customers who are equally accomplished.
<div id="attachment_22394" style="width: 297px" class="wp-caption alignright"><img loading="lazy" decoding="async" aria-describedby="caption-attachment-22394" class="size-medium wp-image-22394" src="https://blog-api.23andme.com/wp-content/uploads/2015/04/Ann_cropped_modified-287x300.jpg" alt="Dr. Ann Turner, MD" width="287" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2015/04/Ann_cropped_modified-287x300.jpg 287w, https://blogcms.23andme.com/wp-content/uploads/2015/04/Ann_cropped_modified.jpg 355w" sizes="auto, (max-width: 287px) 100vw, 287px" />Dr. Ann Turner, MD</div>
One of those is Dr. Ann Turner, a 23andMe Ancestry Ambassador and physician. Ann was recently listed as a co-author on <a href="http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1005137" target="_blank" rel="noopener">a paper</a> published by researchers from the University of Iowa about a genetic variant involved in hearing loss. It turned out to be in a gene that was not even known to be important for the sense of hearing.
“My main contribution was recruiting enough cousins to isolate the segment that must of necessity harbor the mutation,” said Ann.
What’s inspiring is that the impetus for this research was Ann’s own quest to learn about the genetics behind her and her family’s hearing impairment.
Her own hearing loss started in childhood and got progressively worse over time. She’s been wearing hearing aids for 40 years now. Worldwide hearing impairment impacts over five percent of the population, or about 360 million people. Although many different genetic mutations are involved in hearing loss, in this case the researchers were able to isolate a single mutation involved in this one family’s loss of hearing.
Ann’s own <a href="https://blog.23andme.com/articles/tracking-down-a-trait" target="_blank" rel="noopener">personal search</a> of the genetics behind the trait included work going back more than 20 years. She used traditional genealogical techniques to trace hearing loss back 200 years in her family to an ancestor named John Riley, who was born in 1813. One of her relatives, James Riley, a Civil War veteran, died from a fall after failing to hear a warning from a co-worker that the scaffolding he was on was not secure.
<div id="attachment_22396" style="width: 310px" class="wp-caption alignright"><img loading="lazy" decoding="async" aria-describedby="caption-attachment-22396" class="size-medium wp-image-22396" src="https://blog-api.23andme.com/wp-content/uploads/2015/04/HOMER2_pedigree-300x162.jpg" alt="This is a pedigree Ann did of her family showing how tracing the mutation through generations of her family." width="300" height="162" srcset="https://blogcms.23andme.com/wp-content/uploads/2015/04/HOMER2_pedigree-300x162.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2015/04/HOMER2_pedigree.jpg 679w" sizes="auto, (max-width: 300px) 100vw, 300px" />This is a pedigree Ann did of her family showing how tracing the mutation through generations of her family.</div>
Beyond paper records and family trees, Ann also used her and her cousins’ 23andMe results to try and track down the genetics behind their hearing condition. She participated in 23andMe’s exome pilot project a few years ago. This allowed her to obtain the sequence data for all the coding regions of all genes, and she was in turn able to use that data to point to candidate mutations possibly involved in her family’s hereditary hearing loss. “Even though this type of testing is not designed to discover rare or novel mutations, I could roughly narrow down the chromosomal region where the mutation must be located,” Ann said. By looking at her and her family member’s data she was able to identify places where only those with hearing loss shared DNA segments.
“It finally boiled down to just one region by the time all of our results were compared. I wrote about this in a blog post for 23andMe,” she said. The candidate mutation is in the HOMER2 gene. Following up on that work, researchers at the University of Iowa did what are called “functional studies” looking at how that specific genetic mutation affected zebrafish and mice in the lab. The researchers initially found that the loss of function of HOMER2 gene caused by this mutation led to changes in hair cells in the lateral line organ of the zebrafish, which detects movement in the surrounding water. In an email Ann sent to the family members who participated in the research she referenced what researchers did next in their study of mice.
“When (the researchers) did a &#8220;knockdown&#8221; of the HOMER2 gene (made it completely non-functional), the mice developed an early onset hearing loss. It was progressive and started in the high frequencies first, just like our family,” she told her family.
“Our data offer novel insights into gene pathways essential for normal auditory function and the maintenance of cochlear hair cells,” according to the paper’s authors. For Ann the finding was both illuminating for her own family’s condition, but also interesting from her point of view as a scientist. “I have a sense of wonder at how this study illustrates the unity of life, with changes in the lateral line organ in fish confirming the functional effect of the mutation,” she said. Ann adds that other families may be able to use 23andMe tests to help identify the cause of some genetic trait or condition.
For Ann the finding was both illuminating for her own family’s condition, but also interesting from her point of view as a scientist.
“I have a sense of wonder at how this study illustrates the unity of life, with changes in the lateral line organ in fish confirming the functional effect of the mutation,” she said. Ann adds that other families may be able to use 23andMe tests to help identify the cause of some genetic trait or condition.
The candidate mutation is in the HOMER2 gene. Following up on that work, researchers at the University of Iowa did what are called “functional studies” looking at how that specific genetic mutation affected zebrafish and mice in the lab. The researchers initially found that the loss of function of HOMER2 gene caused by this mutation led to changes in hair cells in the lateral line organ of the zebrafish, which detects movement in the surrounding water. In an email Ann sent to the family members who participated in the research she referenced what researchers did next in their study of mice.
“When (the researchers) did a &#8220;knockdown&#8221; of the HOMER2 gene (made it completely non-functional), the mice developed an early onset hearing loss. It was progressive and started in the high frequencies first, just like our family,” she told her family.

Citizen Scientist

A new study by researchers from Stanford Medical School and 23andMe is the first to identify genetic variants associated with rosacea, a chronic skin disease estimated to affect more than 16 million people in the United States alone.<img loading="lazy" decoding="async" class="alignright size-medium wp-image-22186" src="https://blog-api.23andme.com/wp-content/uploads/2015/02/Skin-Graphic-300x300.jpg" alt="Skin Graphic" width="300" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2015/02/Skin-Graphic-300x300.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2015/02/Skin-Graphic-150x150.jpg 150w, https://blogcms.23andme.com/wp-content/uploads/2015/02/Skin-Graphic-271x271.jpg 271w, https://blogcms.23andme.com/wp-content/uploads/2015/02/Skin-Graphic-372x372.jpg 372w, https://blogcms.23andme.com/wp-content/uploads/2015/02/Skin-Graphic-574x574.jpg 574w, https://blogcms.23andme.com/wp-content/uploads/2015/02/Skin-Graphic.jpg 600w" sizes="auto, (max-width: 300px) 100vw, 300px" />


Led by <a href="https://stanfordhealthcare.org/doctors/c/annelynn-chang.html" target="_blank" rel="noopener noreferrer">Dr. Anne Lynn S. Chang</a>, of Stanford University’s School of Medicine, the <a href="https://www.nature.com/jid/journal/vaop/naam/abs/jid201553a.html#close" target="_blank" rel="noopener noreferrer">study</a> to be published in the Journal of Investigative Dermatology, is the first to identify genetic factors for this common but incurable condition. (The link is to a pre-print version of the paper.)
Although the genetic basis for rosacea has long been hypothesized, this is the first study to find genetic variants associated with the condition.
The genes identified in the study support the concept of a genetic basis for rosacea and that could in turn help identify new targets for future studies to better understand and treat this condition. 


The discovery portion of the study, which involved the consented participation of more than 22,000 23andMe customers, found two genetic variants strongly associated with the disease among people of European ancestry. Of the 22, 000 customers in this part of the study, more than 2,600 of them had rosacea and the other 20,000 did not have the condition and were used as controls.


Although rosacea is not life threatening, it is a serious and still little understood condition. Some of the symptoms include redness, inflammation, visible blood vessels, pimple like sores on the skin of the central face, as well as burning and itching. Left untreated it can lead to more serious complications, including disfiguring of the nose – called rhinophyma – and damage to the cornea causing vision problems. Because the condition is so visible it can make those who have it feel isolated.
&#8220;This is also another example of how 23andMe can help in researching common yet understudied diseases,” said 
Joyce Tung, PhD, 23andMe’s Director of Research and a co-author of the paper.


Another intriguing finding from this study is that the single nucleotide polymorphisms (SNPs) found to be strongly associated with the condition, are in or near genes associated with other diseases including diabetes and celiac disease.
One of the SNPs found strongly associated with the condition, , is between the genes HLA-DRA and BTNL2. The HLA-DRA gene is involved in histocompatibility and immune response, which is consistent with the inflammatory nature of rosacea.
To validate the association, 23andMe researchers tested the SNPs from the genome-wide association study in a separate group of 29,000 consented 23andMe customers. The researchers were able to confirm the same association with rosacea.
For that portion of the study, researchers looked at more than 3,000 individuals with rosacea and 26,000 controls.
In addition to the genome wide association study that discovered the variants associated with rosacea, Dr. Chang and her team also took skin biopsies from six individuals with rosacea and showed that both HLA-DRA and BTNL2 proteins can be found in the skin of people with rosacea.
This preliminary works hints toward the biological relevance of HLA-DRA and BTNL2 in rosacea.
The genetic associations found in this study and the associations with other diseases like diabetes and celiac disease may help direct future study.

Genetics found to influence risk for rosacea

Grab a tissue for this. Your genes may make you more prone to cry, and if you cry easily you are at higher odds to have been diagnosed with depression, anxiety or bipolar disorder.<img loading="lazy" decoding="async" src="https://blog-api.23andme.com/wp-content/uploads/2015/03/GeneticsOfCryingInfographic_030615-352x768.jpg" alt="GeneticsOfCryingInfographic_030615" class="alignright size-large wp-image-22302" width="352" height="768" />
Looking at data from 200,000 customers who consented to participate in research, 23andMe scientists found a dozen genetic variants associated with whether a person cries easily.
<h6>Emotional Response</h6>
Crying is an emotional response that makes humans unique from other primates. Some would argue it’s what <a href="http://www.scientificamerican.com/article/why-humans-like-to-cry/" target="_blank" rel="noopener noreferrer">makes us human</a>.
But in 23andMe’s study, researchers wanted to look more deeply into the emotional response. They wanted to know whether there were genetic reasons for some of us crying more easily than others.
Some of the research findings were presented last year at the <a href="https://blog.23andme.com/23andme-research/23andmes-research-at-ashg-2014/" target="_blank" rel="noopener noreferrer">American Society of Human Genetics</a> annual conference. But this study includes both genetic and non-genetic associations. For instance, the study found that boys do cry, but just not as much as girls. According to the research women are three times more likely to “cry easily” when compared to men. Both men and women are more prone to cry as they age. That is especially true if one of their parents was more likely to cry easily.
<h6>Brain Development</h6>
Beyond those findings, the study offered some interesting avenues for future study. The variants identified were found in or near genes involved with brain development (IRX2 and ZNF423) , hormone synthesis (HSD17B12) and certain mood disorders (6q16.1). This could help researchers studying affective disorders, among other things.
23andMe offers its customers the opportunity to participate in research if they want. They can also opt out of research at any time. We are thankful to our customers who participated, making this and other studies like it possible.
Learn more about participating in research, or opting out of it, here.

Too Many Teardrops

Whether you are more apt to reach for a handful of potato chips or go for the bowl of candy may have something to do with your genetics.<img loading="lazy" decoding="async" src="https://blog-api.23andme.com/wp-content/uploads/2015/03/Salty-Sweet-2-300x114.jpg" alt="Salty Sweet 2" class="alignright size-medium wp-image-22298" width="300" height="114" srcset="https://blogcms.23andme.com/wp-content/uploads/2015/03/Salty-Sweet-2-300x114.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2015/03/Salty-Sweet-2.jpg 560w" sizes="auto, (max-width: 300px) 100vw, 300px" />


23andMe scientists identified genetic markers associated with preferring sweet snacks to salty or savoury ones.

 

<h6>Genetics of Taste Preference</h6>
Your age and culture influences the food you like. But genetics plays an important role too.
23andMe customers were evenly split about whether they preferred a <a href="https://www.23andme.com/topics/traits/sweet-salty/">salty snack or a sweet one</a>. But looking at the data, researchers here found several genetic markers associated with preferring sweet snacks over salty ones. 
23andMe’s study found that individuals several variants associated with a preference for sweets.

One of the many interesting aspects of this finding is that both of these genetic markers are in genes that are associated either with metabolism or body mass.
The marker is in the gene FGF21 and the other marker is located in the FTO gene.
<h6>Obesity</h6>
Unlike other studies where genetic markers that influence food preference were found in genes associated with taste receptors on the tongue. These genes are more associated with how people metabolize food. They could offer more insight for researchers studying diabetes, obesity and nutrition.


Writing recently in the <a href="https://www.nytimes.com/2015/01/01/science/gene-linked-to-obesity-hasnt-always-been-a-problem-study-finds.html" target="_blank" rel="noopener noreferrer">New York Times</a>, Carl Zimmer explained how variants in the FTO gene now associated with obesity may have offered an evolutionary advantage. Now, however, with more sedentary lives those variants could be detrimental to people’s health.
23andMe researchers compiled a white paper looking at these and 27 other variants associated with taste preference.
To find out more you can download the paper <a href="https://blog-api.23andme.com/wp-content/uploads/2015/03/5-N8XiOLkGIgydwX_SS-IQ_23-08_Genetic_Associations_With_Traits1.pdf" target="_blank" rel="noopener noreferrer">here</a>.

Salty Or Sweet

We’re feeling a little dizzy trying to keep track of all the coverage 23andMe’s new study on motion sickness received or it might just be this infographic.


The<a href="http://hmg.oxfordjournals.org/content/early/2015/01/26/hmg.ddv028.abstract?keytype=ref&#038;ijkey=2ntxck5YUKc8QSA"> paper</a>, which came out in late January, was the first ever genome-wide association study of the very common condition.
We want to share with you some of the better stories, including coverage in<a href="https://www.fastcompany.com/3042008/feeling-woozy-23andme-releases-first-ever-genome-wide-study-of-motion-sickness"> Fast Company</a>, the<a href="http://www.theatlantic.com/health/archive/2015/02/the-mysterious-science-of-motion-sickness/385469/"> Atlantic</a> and<a href="https://time.com/3695231/23andme-motion-sickness/"> Time</a>. We also wanted to share some of the findings in the study using this fun infographic.
In the study, 23andMe researchers found 35 genetic variants that were significantly associated with motion sickness. Some of those variants, which were identified for the first time, are in or near genes involved in the development of the eye and ear, while other variants appear to be involved in neurological processes and the regulation of glucose and insulin.
The work also confirmed previously known phenotypic associations between motion sickness and other conditions such as migraines, vertigo, and morning sickness as well as postoperative nausea and vomiting.


Note: this post has been altered from the original; the accompanying  graphic has been removed, along with select text.

Feeling Woozy, Motion Sickness Redux

It turns out that whether you like dark chocolate or milk chocolate may have a little bit to do with your genetics. 
<img loading="lazy" decoding="async" class="alignright size-medium wp-image-22200" src="https://blog-api.23andme.com/wp-content/uploads/2015/02/ValentinesDay-300x300.jpg" alt="ValentinesDay" width="300" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-300x300.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-150x150.jpg 150w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-768x768.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-1024x1024.jpg 1024w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-880x880.jpg 880w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-1180x1180.jpg 1180w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-271x271.jpg 271w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-372x372.jpg 372w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-574x574.jpg 574w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay-980x980.jpg 980w, https://blogcms.23andme.com/wp-content/uploads/2015/02/ValentinesDay.jpg 1200w" sizes="auto, (max-width: 300px) 100vw, 300px" /> 
We know that our bitter and sweet taste perceptions are highly associated with different genetic variants.
A lot of work has focused specifically on bitter taste perception associated with a variant in the <a href="https://blog.23andme.com/articles/tasty-genetics" target="_blank" rel="noopener noreferrer">TAS2R38 gene</a>. Some people have it and some don’t.
About a quarter of 23andMe customers don’t have the bitter taste variant. This makes them more likely to have a taste for hoppy beer, broccoli or dark chocolate. A variant in theTAS2R38 gene enables some to perceive the bitterness of the chemical propylthiouracil, or PROP. Some so-called supertasters not only perceive bitterness but also can discern more saltiness, sweetness and spice. This suggests that there are other genes involved in our food preference.
So of course the TAS2R38 variant doesn’t explain everything. While surveys of in the United States show that more than half of Americans prefer milk chocolate to dark, among 23andMe customers dark chocolate wins out. Almost half of 23andMe customers prefer dark chocolate. About 39 percent say they like milk chocolate. That may have to do with genetics, but it is more likely related to a mix of other non-genetic factors.
And there are plenty of genetic factors that researchers are still exploring. For instance, a genome wide association study done last year <a href="http://www.newscientist.com/article/dn25672-unravelling-taste-genes-could-help-us-eat-healthily.html#.VN454cYiQih" target="_blank" rel="noopener noreferrer">found 17 genes</a> related to liking certain foods. Thos foods include among other things dark chocolate, blue cheese and liver. These genes belong to the groups of genes that apparently have nothing to do with taste or smell perception.
All this just goes to show that, like love, our food preferences are complicated.

Health + Traits — Page 23