An editorial in today’s Science Translational Medicine about traumatic brain injuries, genetics, and the long-term risks of degenerative brain disease caught our eye.
<img loading="lazy" decoding="async" class="alignright wp-image-22084 size-medium" title="Anne black and white" src="http://35.88.189.111/wp-content/uploads/2015/01/Anne_Color_-Seated-250x300.jpg" alt="" width="250" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2015/01/Anne_Color_-Seated-250x300.jpg 250w, https://blogcms.23andme.com/wp-content/uploads/2015/01/Anne_Color_-Seated-768x923.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2015/01/Anne_Color_-Seated-852x1024.jpg 852w, https://blogcms.23andme.com/wp-content/uploads/2015/01/Anne_Color_-Seated-732x880.jpg 732w, https://blogcms.23andme.com/wp-content/uploads/2015/01/Anne_Color_-Seated-982x1180.jpg 982w" sizes="auto, (max-width: 250px) 100vw, 250px" />
<h2>Long-Term Risks</h2>
According to the authors, the suicide of former star NFL linebacker Junior Seau, a death that mirrored other suicides of former NFL players who’d suffered degenerative brain damage, prompted them to provocatively ask whether prospective players of high-impact sports or future soldiers should be genotyped to gauge their <a href="http://www.nejm.org/doi/full/10.1056/NEJMp1007051">long-term risks from traumatic brain injuries</a>.
<a href="http://www.mountsinai.org/profiles/samuel-e-gandy">Sam Gandy</a> and Steven T. DeKosky point out that studies clearly link a person’s APOE-4 status – a genetic variant associated with higher risks for Alzheimer’s disease – with an increased risk for degenerative brain disease in response to traumatic brain injuries.
<h2>Would You Want to Know?</h2>
Would you want to know if your son or daughter had a higher risk?
I would.
In fact, I do know because my kids have been tested. Interestingly, Gandy and DeKosky asked about 100 traumatic brain injury experts whether they thought genotyping future athletes or soldiers was worthwhile. Most said it was too soon. But when asked whether they’d have their children genotyped to gauge the risk, more than half said they would.
I thought that was telling.
<h2>Who is at risk for TBIs?</h2>
It’s not just professional athletes and soldiers who are at risk from traumatic brain injury.
More than 1.7 million people a year sustain a traumatic brain injury, and about 50,000 of them die each year, according to the Centers for Disease Control. There are both emotional and financial costs from these injuries.
It’s worth knowing more about the complicated environmental and genetic factors that could explain why traumatic brain injuries lead to long-term disabilities in some people and not in others.
Gandy and DeKosky’s paper is focused on APOE-4, traumatic brain injury, and the risk of one form of degenerative brain disease.
<h2>23andMe Research</h2>
23andMe is looking more broadly at this issue, studying the complicated interaction between our genetics and environment. This can tell us a lot about health risks. It’s often said that our genetics “loads the gun, while the environment pulls the trigger.” In the case of traumatic brain injuries, there is increasing evidence of this interaction.
<img loading="lazy" decoding="async" class="alignright size-medium wp-image-12771" title="Boxinggloves" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/Boxinggloves-200x300.jpg" alt="" width="200" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/05/Boxinggloves-200x300.jpg 200w, https://blogcms.23andme.com/wp-content/uploads/2012/05/Boxinggloves.jpg 283w" sizes="auto, (max-width: 200px) 100vw, 200px" />
Recently we began genotyping professional boxers involved in a study conducted by the Cleveland Clinic Lou Ruvo Center for Brain Health. This landmark study of professional fighters will help determine whether magnetic resonance imaging of the brain, along with other tests, can detect subtle changes in brain health that correlate with impaired thinking and functioning in response to boxing or head trauma. 23andMe is genotyping these athletes to help determine if there might be any genetic association that would make the athletes more or less susceptible to long-term brain injuries.
<h2>Learn More</h2>
Our researchers are also looking in other areas. 23andMe’s innovative research model allows us to track the relationship between certain genotypes and long-term disease. We’ve asked members of our Parkinson’s Research Community about their history of head trauma, for instance, and we can follow our community members over time, giving us insight into the connection between genetics, environmental factors, and long-term outcomes.
If the experts in traumatic brain injury think there&#8217;s value in using genotyping to gauge the risks of high-impact sports for their own children, as noted by the authors in the Science paper, it must be of value to others, too.

23andMe Blog

23andMe Blog Team

Genetics and the Risks from Traumatic Brain Injuries

Two of the biggest physical milestones in a woman’s life are menarche (pronounced “MEN-ar-kee”), the first menstrual period in girls, and menopause, when menstruation stops and female reproductive hormones slow. These milestones are universal and mark the beginning and end of a woman’s reproductive cycle.
<img loading="lazy" decoding="async" class="aligncenter size-medium wp-image-12789" title="2012-nwhw-web-banner" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/2012-nwhw-web-banner-300x76.png" alt="" width="300" height="76" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/05/2012-nwhw-web-banner-300x76.png 300w, https://blogcms.23andme.com/wp-content/uploads/2012/05/2012-nwhw-web-banner.png 408w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Research suggests that the age at which menarche and <a href="https://www.ncbi.nlm.nih.gov/pubmed/15769979" target="_blank" rel="noopener">menopause</a> occur is about 50% influenced by genetics and 50% determined by non-genetic factors, though there is also some evidence that menarche may be more strongly influenced by genetics than menopause.
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Marking Menarche 
Menarche marks an important rite of passage because it signals the possibility of fertility although <a href="https://www.ncbi.nlm.nih.gov/pubmed/6249519" target="_blank" rel="noopener">ovulatory cycles don’t typically begin</a> for a few more years. Many cultures have traditionally recognized this time in a girl’s life through celebrations, ceremonies, or other rituals. In Japan, “red rice” (<a href="https://en.wikipedia.org/wiki/Sekihan" target="_blank" rel="noopener">sekihan</a>) is customarily served for a girl’s first period and Navajo Native Americans have celebrated this time with <a href="http://voices.yahoo.com/native-american-culture-perspectives-kinaalda-the-144347.html?cat=9" target="_blank" rel="noopener">Kinaalda</a>, which translates as “puberty ceremony”. During this four-day ritual girls run footraces to exhibit their strength and are initiated into womanhood with a ceremony. Such rituals are less commonly observed today.
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<h6>Age at Menarche</h6>
<a href="https://www.ncbi.nlm.nih.gov/pubmed/12509562" target="_blank" rel="noopener">Studies have found</a> that nearly all girls in the US menstruate by the age of 14, with the median age around 12 and one-half years. These numbers <a href="https://www.nytimes.com/2010/08/09/health/research/09puberty.html" target="_blank" rel="noopener">haven’t really changed</a> over the last few decades, although <a href="https://www.nytimes.com/2010/08/09/health/research/09puberty.html" target="_blank" rel="noopener">girls today</a> may show signs of puberty (breast growth and pubic hair display) at a younger age. The average age of menarche can vary by ethnicity, though, and <a href="https://www.ncbi.nlm.nih.gov/pubmed/12509562" target="_blank" rel="noopener">African-American girls typically start menstruating</a> before girls of European descent.
In addition to genetics, timing of menarche is influenced by environmental factors such as nutritional status and exercise. Early menarche has been associated with increased risk for breast cancer and endometrial cancer, a connection that many theorize is related to the body&#8217;s exposure to estrogen, a female reproductive hormone.
<h6>Age at Menopause</h6>
Menopause typically occurs between the ages of 40 and 60 with the <a href="http://www.nia.nih.gov/health/publication/menopause" target="_blank" rel="noopener">average age around 51 years</a>. A woman knows that she’s entering menopause if she experiences hot flashes, difficulty sleeping, irregular libido, and mood swings, symptoms that can sometimes be alleviated by hormone replacement therapy. A small fraction of women experience “early menopause” in their 30s, which can cause fertility problems and may also be influenced by genetic factors.
<h6>Research on Menarche and Menopause</h6>
Although some genome-wide association studies have been carried out to identify genetic factors for age at menarche, much less is known about the genetics underlying age at menopause. These important milestones are known to be influenced by ancestral origin, though more research is needed to identify genetic factors in non-European populations.
It&#8217;s National Women&#8217;s Health Week. Stay tuned for more posts about big health issues facing women today including autoimmune diseases, infertility and breast cancer.

From Menarche to Menopause

Mothers are special on so many levels. We cherish them for loving us and imparting important life lessons&#8230; and for giving us <a href="https://en.wikipedia.org/wiki/Mitochondrion" target="_blank" rel="noopener noreferrer">mitochondria</a> (or &#8220;mito&#8221; for short)! Mitochondria are small, roundish structures inside of cells that produce cellular energy. They have &#8220;zigzag insides&#8221; and their own DNA, which can be used to trace a person&#8217;s maternal line.
<img loading="lazy" decoding="async" class="aligncenter wp-image-12805" title="mothers day card v3" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/mothers-day-card-v3-1024x489.png" alt="" width="608" height="290" />
Mother&#8217;s day marks the beginning of National Women&#8217;s Health Week. We&#8217;ll be running posts all week about universal female milestones (menarche and menopause) and a variety of other women&#8217;s health topics. Stay tuned!
<img loading="lazy" decoding="async" class="aligncenter size-full wp-image-12789" title="2012-nwhw-web-banner" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/2012-nwhw-web-banner.png" alt="" width="408" height="104" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/05/2012-nwhw-web-banner.png 408w, https://blogcms.23andme.com/wp-content/uploads/2012/05/2012-nwhw-web-banner-300x76.png 300w" sizes="auto, (max-width: 408px) 100vw, 408px" />

Thanks for the Mito Mom!

Cancer is not one disease, but many.
Even looking specifically at breast cancer or sarcoma, the more researchers study these diseases, the more they understand that there are many different kinds of breast cancer and sarcoma.
This has been one of the most challenging aspects of researching cures for cancer.
This month is National Cancer Research Awareness Month, and 23andMe is highlighting our work in cancer research. We’re also talking to some of the people involved in the research and letting you know about some of the more exciting developments in the field.
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&#8211; Do you have sarcoma, or know someone who does? Learn how to join our <a href="https://www.23andme.com/sarcoma/">Sarcoma research community today</a>.
&#8211; Do you have an MPN, or know someone who does? Learn how to join our <a href="https://www.23andme.com/mpn/">MPN research initiative today</a>.
&#8211;   If you or someone you know has been diagnosed with metastatic breast cancer, check out our <a href="https://www.23andme.com/invite-study/">innovative online study with Genentech</a>.
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Earlier this year, George Demetri, a doctor and scientist who is an unpaid advisor to our<a href="https://www.23andme.com/sarcoma/"> Sarcoma research initiative</a>,<a href="../2012/03/12/talking-about-sarcoma-with-george-demetri/"> noted how different sarcomas</a> were. Not just under the microscope but when you look at them at the genetic level. Dr. Demetri said, this is where 23andMe’s research model offers so much promise. Using genetics may help us connect the right patient to the right drug. It can help change the one size fits all approach to clinical research and it holds the promise of other targeted medicines.
Scientists have found specific mutations that drive specific forms of cancer. There is already a long list of successes, Demetri said, whether from a drug that targets the HER2 protein in certain types of breast-cancer, or  from the use of Gleevec to target a specific protein in the treatment of chronic myeloid leukemia. 
Right now, 23andMe has three studies focused on cancer.
We first applied our unique research platform to study cancer in April 2010 with the launch of our <a href="https://www.23andme.com/sarcoma/">Sarcoma Research Initiative</a>. We are already very close to reaching our goal of enrolling 1,000 people with the disease. Last summer we launched a <a href="https://www.23andme.com/mpn/">Myeloproliferative Neoplasms Research Initiative</a> to study this group of very rare blood cancers. More than 650 patients have joined this research project in just 9 months, and we announced our first research finding earlier this year. Finally, we’ve joined forces with Genentech to start a<a href="https://www.23andme.com/invite-study/"> unique online breast cancer study</a> to look at how genes influence a person’s response to treatment for metastatic breast cancer.
In each of these studies we believe we can change how clinical trials and cancer research is done. We want to make it cost less and take less time. We want to leverage the power of the web to bring down some of the barriers to participate and give people access to their genetic data in the process.
23andMe was started on this premise, and our research communities are the embodiment of that goal. Patients from all over the world can contribute directly to research and connect with others who have their disease, all while learning more about themselves.
We are also always looking for other genetic associations with cancer, and currently have two separate Cancer Family History Surveys, one for men and one for women.
We hope that over time this work will lead to important breakthroughs in the fight against cancer. Over the next few weeks we’ll be posting more stories about cancer, the research going on to fight the disease and some of the people at the forefront of that work. Stay tuned.

National Cancer Research Awareness Month

<img loading="lazy" decoding="async" class="alignnone size-medium wp-image-12723" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/eggHead-300x199.jpg" alt="" width="300" height="199" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/05/eggHead-300x199.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2012/05/eggHead.jpg 425w" sizes="auto, (max-width: 300px) 100vw, 300px" />
If you have a big head, you may be subjected to a fair bit of teasing, but science may offer you some consolation. For instance, individuals with a smaller intracranial volume (the area within the skull) are at slightly higher risk for late-life dementia. In addition, a smaller hippocampus (a section of the brain involved in learning and memory storage) has been associated with Alzheimer’s disease and mental illnesses such as depression and schizophrenia. Four papers published recently in Nature Genetics address various measures of head size and their possible health implications.
 
Factors influencing infant head circumference 
An international team of scientists, led by H. Rob Taal from the Erasmus Medical Center in the Netherlands, has attempted to answer the question that has plagued numerous women in labor &#8212; why is my baby’s head so large?
Head size as an infant is highly heritable, meaning genetics accounts for a large portion of infant head circumference variability. To determine which genetic factors are involved, the team of researchers looked at genetic data from over 19,000 infants with European ancestry. They <a href="https://www.ncbi.nlm.nih.gov/pubmed/22504419" target="_blank" rel="noopener">found</a> that, on average, infants with the CC genotype at in the HMGA2 gene had heads that were approximately 1 mm larger around than infants with the CT genotype, and infants with the TT genotype had on average heads that were 1 mm smaller around. In addition, they found that each A at in SBNO1 gene was associated with approximately 1.2 mm larger head circumference.
Both of these SNPs are associated with height in adults. SBNO1, however, may play more of a role in neurological development; a similar gene found in fruit flies is related to development of a fly’s central nervous system.
Factors influencing intracranial volume 
Early in life, brain volume and skull size are highly correlated. However, at a certain point the brain stops growing and begins to shrink while the skull remains the same size. Intracranial volume, which is the volume within the skull, is thus considered a good proxy for an individual’s maximum adult brain size.
Two of the recent Nature Genetics papers studied genetic factors influencing intracranial volume. A group of researchers led by Jason Stein from David Green School of Medicine at the University of California, Los Angeles, <a href="https://www.ncbi.nlm.nih.gov/pubmed/22504417" target="_blank" rel="noopener">discovered</a> that the SNP within the HMGA2 gene on chromosome 12 is associated with intracranial volume. The study, which used magnetic resonance imaging (MRI) to measure the skull size of over 15,000 individuals of European ancestry, suggests that the CC genotype at is associated with a 9.1 mL increase in intracranial volume over individuals with the CT genotype, and that the TT genotype was associated with a 9.1 mL decrease in intracranial volume.
Although the HMGA2 gene has been associated with height, this did not seem to fully account for the observed association between the SNP and intracranial volume. In a smaller, follow-up analysis the researchers also found that the C version of this SNP was associated with a very slight increase in IQ. But don’t “get a big head” about it if you happen to be CC at this SNP &#8212; the evidence was fairly weak and more research is needed to confirm these findings.
Another large team of researchers, led by M. Arfan Ikram, from the Erasmus Medical Center in the Netherlands, <a href="https://www.ncbi.nlm.nih.gov/pubmed/22504418" target="_blank" rel="noopener">found</a> two other SNPs influencing intracranial volume: on chromosome 6 and on chromosome 17. Each G at was associated with a 12.5 mL increase in intracranial volume, and each G at was associated with a 15 mL decrease in intracranial volume in a study of nearly 82,000 elderly individuals of European ancestry.
Factors influencing hippocampal volume 
The hippocampus is a segment of the brain involved in learning and storing memories, and the size of the hippocampus has medical significance. A smaller hippocampal volume has been associated with depression, schizophrenia, and types of epilepsy. In addition, the hippocampus is often one of the first areas of the brain to be affected by Alzheimer&#8217;s disease, making it an early indicator of this disease.
A team of researchers led by Joshua C. Bis from the Department of Medicine at the University of Washington in Seattle looked at over 19,000 people with European ancestry and <a href="https://www.ncbi.nlm.nih.gov/pubmed/22504421" target="_blank" rel="noopener">found</a> that the C version at near the HRK-FBXW8 gene is associated with a 0.11 mL increase in hippocampal volume. Since the hippocampus shrinks as one ages, the authors equated this hippocampus size difference to a decrease of 3.9 years of age.
If your head is larger than most, be grateful for your possible lower risk of certain diseases and potentially higher IQ. But don’t let it go to your head &#8212; perhaps you should thank your parents for your big-head genes. Indeed, given the trouble your big noggin caused her, perhaps you should especially thank your mother this Mother’s Day!

Do These Genes Make My Brain Look Big?

<img loading="lazy" decoding="async" class="alignright size-medium wp-image-6465" title="Tummy Time!" src="https://blog-api.23andme.com/wp-content/uploads/2010/04/iStock_000001348449XSmall-300x199.jpg" alt="" width="300" height="199" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/04/iStock_000001348449XSmall-300x199.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2010/04/iStock_000001348449XSmall.jpg 425w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Nature vs. nurture is a question scientists and non-scientists alike have grappled with since the earliest days of human history. One concept we use to describe these two complementary forces is &#8220;heritability&#8221;, or the proportion of variation in the development of a disease or trait in a population that&#8217;s due to genetics.
While this sounds simple, there are some nuances to heritability that often cause it to be misinterpreted. Show us what you know about heritability in this week&#8217;s quiz!
<a title="Quiz Answers: Heritability Demystified" href="https://blog.23andme.com/articles/quiz-answers-heritability-demystified">This quiz is now closed. See the answers here!</a>

What Do You Know About Heritability?

Last week we quizzed our readers on traits associated with BMI among 23andMe’s customers. Congratulations to Suellen, the winner of the quiz! She got all three answers correct and will receive an Amazon gift card. So what were the correct answers? Read on&#8230;
Which physical trait is most associated with BMI? Shoe size.
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Shoe size is very strongly correlated with BMI in 23andMe’s database. For each standard deviation increase in shoe size, BMI increases by 1.18 units. Put another way, the BMI of the bottom fifth of the shoe size distribution is 3.21 units lower on average than that of the top fifth. This corresponds to a difference of about 20 lbs in people who are 5’8” tall.
We’re really not sure what to make out of this one. Shoe size is also correlated with height but when we factored height into the analysis shoe size was still the most strongly correlated trait. Anecdotally, people’s shoe sizes can increase or decrease with weight gain and loss. It’s possible that people with wider feet may compensate by increasing their shoe size instead of choosing a wider shoe of the same size, or perhaps shoe size is a proxy for body frame, and people with larger shoe sizes have “bigger bones”. Have a theory? Add it to the comments below.
Having a round face, low arches, upturned nose, and feet that point outwards are also associated with BMI but to a lesser extent.
Which food item is most associated with BMI? Diet soda.
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The surprise for us here was that ice cream consumption was not really correlated with BMI at all. On the other hand, people who drink diet soda five or more times a day have an average BMI nearly 5 units higher than those who never drink diet soda. Not to imply that we should all trade in that diet coke for a double hot fudge sundae &#8212; we don’t know whether drinking soda is a cause, a consequence, or just linked to something else that causes weight gain. These findings do, however, parallel that of a study conducted in Texas, in which normal weight individuals were followed for 8 years. People who reported drinking more diet soda gained more weight over those 8 years, suggesting that diet soda might actually lead more directly to weight gain.(1) But for now, the jury’s still out.
Some other foods were associated with BMI, too, including red meat, yogurt, and vegetables.
Which personality or behavior trait is most associated with BMI? Activity and depression.
<div style="margin-top: 15px; margin-bottom: 15px; border: 1px solid #ccc; width: 600px;"><img decoding="async" class="aligncenter size-large wp-image-12688" title="BMI-personality" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/BMI-personality-1024x549.png" alt="" width="600" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/05/BMI-personality-1024x549.png 1024w, https://blogcms.23andme.com/wp-content/uploads/2012/05/BMI-personality-300x161.png 300w, https://blogcms.23andme.com/wp-content/uploads/2012/05/BMI-personality-768x412.png 768w, https://blogcms.23andme.com/wp-content/uploads/2012/05/BMI-personality-880x472.png 880w, https://blogcms.23andme.com/wp-content/uploads/2012/05/BMI-personality-1180x633.png 1180w" sizes="(max-width: 1024px) 100vw, 1024px" /></div>
These are less of a surprise. Activity is strongly correlated with BMI, and is no doubt due to the calorie burning benefits of exercise. The reverse may also be true &#8212; being overweight may itself decrease activity levels, creating a vicious cycle.
For depression, the arrow of causation seems to point in both directions. For example, a recent meta-analysis found that being overweight or obese increased the risk of developing depression, and having depression increased the risk of becoming obese.(2)
Having greater levels of self-discipline was correlated with lower BMI to a lesser extent, but aside from this we didn’t find a significant relationship between BMI and any other personality factors.
Check back soon for our next quiz and another chance to win!
(1)  Fowler, SP, Williams, K, Resendez, RG, Hunt, KJ, Hazuda, HP, &amp; Stern, MP. (2008). Fueling the Obesity Epidemic? Artificially Sweetened Beverage Use and Long-term Weight Gain. Epidemiology, 16(8): 1894-1900.
(2)  Luppino, FS, de Wit, LM, Bouvy, PF, Stijnen, T, Cuijpers, P, Penninx, BWJH, Zitman, FG (2010). Overweight, Obesity, and Depression: A systematic review and meta-analysis of longitudinal studies. Arch Gen Psychiatry. 2010;67(3):220-229.

Quiz Answers: Traits Associated With BMI

<img loading="lazy" decoding="async" class="alignnone size-medium wp-image-12577" title="Stock Photo" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/Mexican-Heritage-300x197.jpg" alt="" width="300" height="197" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/05/Mexican-Heritage-300x197.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2012/05/Mexican-Heritage.jpg 427w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Today is Cinco de Mayo. This day commemorates the Mexican army&#8217;s 1862 victory over France in the Battle of Puebla (not Mexican independence day as is commonly believed), but is more widely observed in the United States as a celebration of Mexican heritage and pride.
There are different ways to celebrate Mexican culture – <a href="http://www.merriam-webster.com/dictionary/fiesta" target="_blank" rel="noopener noreferrer">fiestas</a> around the country host <a href="http://www.merriam-webster.com/dictionary/mariachi" target="_blank" rel="noopener noreferrer">mariachi</a> performances and a trip to a taqueria shouldn’t be missed. Another way to celebrate Mexican heritage is through DNA.
I reached out to my good friend Miguel who hails from the state of Jalisco in Mexico to see what he’s discovered about his ancestry through <a href="https://www.23andme.com/ancestry/" target="_blank" rel="noopener noreferrer">23andMe&#8217;s Personal Genome Service</a>.
<h6>Native American Ancestry</h6>
Like many Mexicans, Miguel learned through family stories that he has both Native American and European ancestry. It turns out that roughly 69% of his DNA traces to Europe, 28% is suggestive of Native American ancestry, and about 3% traces to Africa.
He’s been told that his Native American ancestry comes from his maternal side and this was confirmed by investigating his <a href="https://www.23andme.com/you/haplogroup/maternal/" target="_blank" rel="noopener noreferrer">maternal line</a>. Miguel’s maternal lineage (C1c) is very old and typically found in Native Americans and native Asian populations. This data contributed to 23andMe’s Native American Ancestry Finder feature proclaiming, “Yes Miguel, it looks likely that you have Native American ancestry”.
His European ancestry comes from his father’s side and this was confirmed by investigating his <a href="https://www.23andme.com/you/haplogroup/paternal/" target="_blank" rel="noopener noreferrer">paternal line</a> (R1b1b2a1a2f), an offshoot of the most common line in western Europe (R1b1b2) and found at high frequency in Basque populations. This fits with what Miguel’s been told about his European roots.
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<img loading="lazy" decoding="async" class="alignnone size-large wp-image-12616" title="Miguel Maternal Line" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/Miguel-Maternal-Line-1024x470.png" alt="" width="600" height="280" /><img loading="lazy" decoding="async" class="alignnone size-large wp-image-12627" title="Miguel Paternal Line" src="https://blog-api.23andme.com/wp-content/uploads/2012/05/Miguel-Paternal-Line-1024x499.png" alt="" width="600" height="280" />
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23andMe customers can learn all about their ancestry in <a href="https://www.23andme.com/you/" target="_blank" rel="noopener noreferrer">their account. 
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Not yet a customer? <a href="https://www.23andme.com/store" target="_blank" rel="noopener noreferrer">Visit our store</a>!
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<h6>Ancestry Finder</h6>
Perhaps the most eye-catching part of Miguel’s DNA voyage is found in his Ancestry Finder profile (see figure below). This feature combines DNA matches (segments of DNA you share with other 23andMe customers) with self-reported ancestry data obtained from our Where Are You From? survey. Based on his results, he shares DNA with several other 23andMe customers who have Mexican and South American ancestors.
Even if you don’t have Mexican ancestry like Miguel, we wish all of you a happy Cinco de Mayo. Go get your taco and toast to Miguel for helping us discover that DNA can help you “cinco” in on your ancestry!
Miguel&#8217;s Ancestry Finder Data 
<img loading="lazy" decoding="async" class="aligncenter wp-image-12645 size-large" title="Ancestry Finder Miguel" src="http://35.88.189.111/wp-content/uploads/2012/05/Ancestry-Finder-Miguel-1024x400.png" alt="" width="1024" height="400" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/05/Ancestry-Finder-Miguel-1024x400.png 1024w, https://blogcms.23andme.com/wp-content/uploads/2012/05/Ancestry-Finder-Miguel-300x117.png 300w, https://blogcms.23andme.com/wp-content/uploads/2012/05/Ancestry-Finder-Miguel-768x300.png 768w, https://blogcms.23andme.com/wp-content/uploads/2012/05/Ancestry-Finder-Miguel-880x343.png 880w, https://blogcms.23andme.com/wp-content/uploads/2012/05/Ancestry-Finder-Miguel-1180x460.png 1180w, https://blogcms.23andme.com/wp-content/uploads/2012/05/Ancestry-Finder-Miguel.png 1502w" sizes="auto, (max-width: 1024px) 100vw, 1024px" />
Interested in ancestry? Read about how <a href="https://blog.23andme.com/articles/ancestry-at-23andme-introducing-sheridan" target="_blank" rel="noopener noreferrer">Sheridan got up to speed</a> on her ancestry and <a href="https://blog.23andme.com/articles/ancestry-at-23andme-what-can-you-learn" target="_blank" rel="noopener noreferrer">get an overview</a> of the breadth 23andMe’s ancestry features. DNA can also offer clues about <a href="../2012/03/16/did-you-know-dna-can-offer-clues-about-irish-ancestry" target="_blank" rel="noopener noreferrer">Irish ancestry</a>.

Zero in on Mexican Ancestry on Cinco de Mayo

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What Causes Parkinson&#8217;s Disease? 

The symptoms of Parkinson’s are thought to stem from a loss of dopamine-producing brain cells that normally control movement, but what causes these cells to die off in the first place is difficult to answer. Toxins and other environmental factors can play a role, but so does genetics. In some cases Parkinson’s is primarily due to genetics, in other cases it is largely environmental, and most of the time it’s a mix of the two.
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About 1.5 million Americans have Parkinson’s and about 50,000 new patients are diagnosed each year. Many of us have seen loved ones suffer through years of trembling and muscle weakness knowing that things will eventually get worse because there isn’t a cure.
But that’s where science comes in. The primary goal of the more than 800 Parkinson&#8217;s genetic association studies published to date is to identify the genetics underlying this condition so that we can understand what goes wrong and develop therapies.
Dozens of genetic factors have been linked to Parkinson’s disease and some of these findings meet 23andMe’s internal scientific standards and are reported to customers. We’ve been providing genetic results for Parkinson’s to customers since 2008 and last week we added five more factors to our report.
(See below for a timeline of 23andMe’s contributions to Parkinson’s research and history of providing customers with genetic results for Parkinson&#8217;s.)
<div style="border: 1px solid #eee; margin-top: 20px; margin-bottom: 15px;"><img loading="lazy" decoding="async" class="alignnone wp-image-12468 size-full" title="Slide2" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/Slide23.jpg" alt="" width="600" height="600" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/Slide23-150x150.jpg 150w, https://blogcms.23andme.com/wp-content/uploads/2012/04/Slide23-271x271.jpg 271w, https://blogcms.23andme.com/wp-content/uploads/2012/04/Slide23-372x372.jpg 372w" sizes="auto, (max-width: 600px) 100vw, 600px" /></div>

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23andMe customers can view their genetic results for Parkinson&#8217;s Disease in their account (note that this report requires an additional opt in).
Not yet a customer? <a href="https://www.23andme.com/store">Visit our store</a>!
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Our first report on Parkinson’s disease included the G2019S mutation in the LRRK2 gene. Only about 1-2% of the general population develops Parkinson’s, but studies have shown that about 50% of people with the G2019S mutation will develop the disease in their life time.
We later added the G2385R mutation in the LRRK2 gene, which is applicable to people with Asian ancestry and is associated with about three times higher odds of developing Parkinson’s.
In April of 2011 (and timed for <a href="http://www.parkinson.org/" target="_blank" rel="noopener noreferrer">Parkinson’s disease awareness</a> month) we added variants in the GBA, SNCA and MAPT genes to our genetic report on Parkinson’s. The N370S mutation in the GBA gene is associated with about four times higher risk of Parkinson’s and may exert its influence by making cells more sensitive to toxins. The rest of the factors reported by 23andMe, including the SNCA and MAPT variants and versions of  PARK16, DGKQ, BST1, STK39 added last week, have much smaller effects on risk for the disease but are much more common in the population than LRRK2 or GBA mutations.
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You Can Help!
<div>For Parkinson’s Awareness Month we’ve posted stories, interviews and given updates on the state of research on Parkinson’s, which includes 23andMe&#8217;s very own <a href="https://www.23andme.com/pd/" target="_blank" rel="noopener noreferrer">Parkinson’s disease research community</a>.</div>
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<div>With your help, we topped our goal of enrolling 7,500 participants by the end of April and are en route to our long-term goal of 10,000 participants.</div>
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<div>If you have Parkinson’s,  <a href="https://www.23andme.com/pd/" target="_blank" rel="noopener noreferrer">join our Parkinson’s community</a> and participate in research. If you don’t have Parkinson’s, contribute by becoming a <a href="https://www.23andme.com/store/cart/" target="_blank" rel="noopener noreferrer">23andMe customer</a>  and answering surveys. You can make a difference!&#8221;</div>
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Alongside reporting genetic results to customers we’ve also been carrying out research on Parkinson’s. Over 7,000 individuals have enrolled in our Parkinson’s Disease community and with their help and the participation of other customers we’ve <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002141" target="_blank" rel="noopener noreferrer">discovered new genetic factors</a> for Parkinson’s that we <a href="https://www.23andme.com/health/Parkinsons-Disease-Preliminary-Research/" target="_blank" rel="noopener noreferrer">report back to our customers</a>. We’ve also identified a genetic factor in a gene called SGK1 that may protect individuals with risky versions of LRRK2 from developing Parkinson’s.
We&#8217;re currently partnering with other researchers to see if this initial finding can lead to new treatments.
People with Parkinson’s disease still suffer too much, but it’s clear that research efforts over the last decade are getting us closer to understanding what causes this disorder. It’s also becoming clear that early detection can help delay the progression of Parkinson’s and that’s good news all around. There are many more outstanding questions, for instance understanding how genetic and environmental factors interact, and hopefully in time we’ll find some answers. The 23andMe community has progressed Parkinson’s research tremendously and we hope that you’ll continue to <a href="https://www.23andme.com/pd/" target="_blank" rel="noopener noreferrer">give us your hand</a> in the years ahead.
The author’s paternal grandfather passed away from Parkinson’s disease in 2005. He was deeply loved and in her thoughts as she wrote this piece.

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