<img loading="lazy" decoding="async" class="alignright wp-image-68 size-medium" title="toast" src="http://35.88.189.111/wp-content/uploads/2008/01/toast-300x188.png" alt="" width="300" height="188" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/01/toast-300x188.png 300w, https://blogcms.23andme.com/wp-content/uploads/2008/01/toast.png 350w" sizes="auto, (max-width: 300px) 100vw, 300px" />
The 23andMe Personal Genome Service offers information about customers&#8217; maternal and paternal ancestry by examining their mitochondrial DNA (which we all inherit from our mothers) and the Y chromosome (passed by fathers to their sons).
Over our species&#8217; history, new genetic variations have arisen spontaneously in those pieces of DNA and passed down through the generations. So researchers know that every person alive today with a particular variation – say a T instead of a G at a specific spot on the mtDNA – is descended from a single common ancestor. By sampling people from around the world, scientists have assembled &#8220;family trees&#8221; that trace back to the dawn of the human species in eastern Africa more than 100,000 years ago. Those trees are the basis of the haplogroup assignments we give our customers. Each haplogroup represents a particular branch – and, therefore, a unique sequence of SNPs.
Now, using a feature we&#8217;ve developed called the Haplogroup Tree Mutation Mapper, you can see exactly which SNPs we use to generate the 23andMe mitochondrial and Y chromosome haplogroup trees. This isn&#8217;t the kind of information everyone would necessarily want, but several customers who are especially interested in genetic genealogy have requested it. It can be used to compare our haplogroup assignments to those obtained elsewhere, for example.

The Haplogroup Tree Mutation Mapper is the first arrival in 23andMe Labs, our new technology sandbox, where we will showcase experimental features not currently available in our Personal Genome Service.   These features may still be in development, require specialized knowledge, or be of interest only to a subset of our customers. Each lab will have its own community so customers can compare notes, ask questions, and share ideas.
Some labs will be requested by customers—in fact, we welcome your suggestions—and others will be dreamed up by our scientists.
Finally, labs will be somewhat less refined and fluid than those available within the Personal Genome Service. A feature could be discontinued at any time or elevated to full integration with our Personal Genome Service.
We&#8217;re really excited about this new outlet for our ingenuity, and we hope it will also engage some of you!

23andMe Blog

23andMe Blog Team

23andMe Labs Kicks Off With Haplogroup Tree Mutation Mapper

<img loading="lazy" decoding="async" class="alignright size-full wp-image-3242" title="colon" src="https://blog-api.23andme.com/wp-content/uploads/2009/04/colon.jpg" alt="" width="360" height="240" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/04/colon.jpg 360w, https://blogcms.23andme.com/wp-content/uploads/2009/04/colon-300x200.jpg 300w" sizes="auto, (max-width: 360px) 100vw, 360px" />
Colorectal cancer is the third most commonly diagnosed cancer in the U.S., and the third leading cause of cancer death.   In 2008 close to 50,000 people succumbed to the disease.
But not all groups are affected equally.   An American Cancer Society study found that colorectal cancer incidence rates are more than 20% higher for African Americans than Caucasians. Death rates from the disease are 45% higher.
Lifestyle factors, access to healthcare and cultural differences have all been proposed as reasons to explain the racial disparities in colorectal cancer survival. But new research from the University of Alabama, published today in the journal <a href="http://clincancerres.aacrjournals.org/cgi/content/abstract/15/7/2406" target="_blank" rel="noopener noreferrer">Clinical Cancer Research</a>, shows that for some African Americans, genetics may play a part too.
Researchers analyzed 373 colorectal tumors — 137 taken from African Americans and 236 taken from non-Hispanic Caucasians.   They found that African American patients with two Gs at in the p53 gene were 2.15 times more likely to die of colorectal cancer than those with one or no copies of a G at this SNP.   In Caucasians there was no association between survival and .
Seventeen percent of African American patients had two Gs at this SNP, while only 7% of Caucasian patients did.
The p53 gene encodes a tumor suppressor protein that protects against cancer, in part, by telling damaged cells to self-destruct instead of turning into tumors.   Mutations in the p53 gene that disrupt its function are a common feature of many cancers. (These mutations are distinct from the variation.)
Although the findings will need to be replicated in larger studies, the study’s authors suggest that might be a race-specific prognostic marker for African American patients with colorectal cancers and that someday analysis of this SNP might aid in designing optimal treatment regimens.

Genetic Variation In Tumor Suppressor May Predict Worse Outcome for African American Colorectal Cancer Patients

<img loading="lazy" decoding="async" class="alignright size-full wp-image-3220" title="skincancer" src="https://blog-api.23andme.com/wp-content/uploads/2009/03/skincancer.jpg" alt="" width="320" height="211" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/03/skincancer.jpg 320w, https://blogcms.23andme.com/wp-content/uploads/2009/03/skincancer-300x198.jpg 300w" sizes="auto, (max-width: 320px) 100vw, 320px" />
Melanoma, a rare but potentially deadly form of skin cancer, is more common in women under 40 than in men in the same age group.   After age 45, the tables are turned: men are more likely to be diagnosed with melanoma.
Between the ages of 40 and 50 happens to be when many women enter menopause or perimenopause, a time of declining estrogen levels.   This has prompted some researchers to suggest that estrogen exposure may play a part in melanoma risk.
In a report published last week in Clinical Cancer Research, researchers show that a genetic variation previously associated with several other cancers may be the link between estrogen and melanoma in younger women.   The riskier version of the variation increases the odds a woman will be diagnosed with melanoma before age 40 more than fourfold.
“Potentially, we have a genetic test that might identify pre-menopausal women who are at higher risk for melanoma.   And if that’s the case, then we might want to have increased surveillance of those patients including more frequent visits to the doctor, more rigorous teaching of skin self-examination, and other preventive steps,” said Dr. David Polsky, the study’s lead author, in a statement.
In a sample of 227 people with melanoma — 93 women and 134 men — researchers found that women with two Gs at a specific SNP in the MDM2 gene were diagnosed with the disease 13 years earlier than those with GT or TT at this SNP.   In men, there was no effect of on age at diagnosis.
About 52% of women with GG at this SNP were diagnosed with melanoma before age 50 — and 38% between ages 30 and 39.   Only about 22% of women with GT or TT were diagnosed before age 50. Although those figures are dramatic, it is important to remember that the SNP was not shown to affect melanoma risk generally, but the age at which people who do develop it are diagnosed.
Laboratory experiments have shown that the G version of this SNP causes the MDM2 gene to be turned on at higher levels in response to estrogen than the T version.
Higher levels of MDM2 protein may be relevant to melanoma, as well as other cancers, because its role in cells is to regulate a tumor suppressor protein called p53.   More MDM2 means less p53, which in turn can reduce a cell’s protection against turning into a cancer cell.
More research will be needed to confirm that there is an interaction between estrogen and the G version of SNP that affects melanoma risk.   The authors caution that their study was small, lacked information about the menopausal status of the women they studied and did not include a group of people without melanoma for comparison.
More work will also be needed to understand how the MDM2 gene and the protein it encodes affect cancer risk in general.   The G version of SNP has been associated with earlier onset for some cancers, including soft tissue sarcoma, diffuse large B-cell lymphoma, colorectal cancer, ovarian cancer and non-small cell lung cancer in women, and decreased survival in people with stomach and kidney cancer.   But there is evidence for improved survival in women with ovarian cancer who have the G version of this SNP.   Paradoxically, higher levels of the MDM2 protein (as would be expected with the G version of SNP shown to lead to earlier melanoma onset in the current study) have been associated with improved survival for melanoma.

Genetic Variation May Explain Why Young Women Are At Greater Risk For Melanoma Compared to Young Men

<img loading="lazy" decoding="async" class="alignright size-full wp-image-3194" title="bloodtravel1" src="https://blog-api.23andme.com/wp-content/uploads/2009/03/bloodtravel1.jpg" alt="" width="318" height="236" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/03/bloodtravel1.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2009/03/bloodtravel1-300x223.jpg 300w" sizes="auto, (max-width: 318px) 100vw, 318px" />
Deep vein thrombosis (DVT), sometimes called “<a href="https://www.ncbi.nlm.nih.gov/pubmed/2900413?dopt=Abstract" target="_blank" rel="noopener noreferrer">economy class syndrome</a>” is the formation of a blood clot in a vein deep within the body, usually in the legs. &nbsp; Not only can DVT be painful, but it can also lead to a potentially fatal condition called pulmonary embolism if the clot breaks free and travels through the circulatory system to the lungs.
In addition to environmental factors, there are genetic variations that can raise a person’s chances of having DVT. &nbsp; But providing genetic testing to everyone is not feasible, leading researchers from the Leiden University Medical Center in the Netherlands to question whether a family history of DVT could also be of value as a risk indicator.
The researchers looked at records and family histories of 3,764 people — 1,605 who had had DVT and 2,159 who had not. &nbsp; Their results, published online this week in the <a href="http://archinte.ama-assn.org/cgi/content/abstract/169/6/610" target="_blank" rel="noopener noreferrer">Archives of Internal Medicine</a>, show that in people with no environmental or genetic risk factors, having a first-degree relative (parentor sibling) with DVT increased the odds of having a first episode of DVT by 2.5 times. &nbsp; This was about the same as the increase in odds (2.3 times) caused by genetic risk factors in people with no family history or environmental risk factors.
Only 29.7% of people with family history of DVT carried a known genetic risk factor, but a family history was more common in DVT patients than controls with similar known genetic and environmental risk factors. &nbsp; This suggests that there are unknown, probably genetic, factors at work. &nbsp; The researchers say that unknown genetic factors probably have small effects that contribute to DVT only when other, larger risk factors are present, such as the factor V Leiden genetic variation or an environmental risk factor such as surgery, immobilization or oral contraceptive use.
Based on the fact that a positive family history increases the risk of DVT to about the same degree as known genetic risk factors, and the fact that most people with a family history of DVT don’t actually carry a known genetic risk factor, the researchers conclude that genetic testing for variations associated with DVT is of little additional value compared to collecting family history alone.
However, while a cost-effectiveness argument might be made, the authors’ own data shows that known genetic risk factors substantially increase the odds of DVT whether or not a person has a family history of the condition. &nbsp; A family history of DVT or a known genetic risk factor alone increases the odds of DVT by about two and a half times, but the presence of both increases the odds by 6.3 times. &nbsp; The presence of an environmental risk factor raises the odds of DVT about nine and half times. &nbsp; Add in a positive family history and the odds go up to more than 16 times those of someone who lacks known risk factors (both genetic and environmental) as well as a family history of DVT. &nbsp; But in those unlucky enough to have a family history of DVT, an environmental risk factor and a known genetic risk factor, the odds of DVT are increased a whopping 64 times.

Family History, In Addition To Genetic and Environmental Risk Factors, Predicts Risk of Deep Vein Thrombosis

<img loading="lazy" decoding="async" class="alignright size-full wp-image-3171" title="101371_journalpmed1000050g001-m" src="https://blog-api.23andme.com/wp-content/uploads/2009/03/101371_journalpmed1000050g001-m.jpg" alt="" width="349" height="223" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/03/101371_journalpmed1000050g001-m.jpg 600w, https://blogcms.23andme.com/wp-content/uploads/2009/03/101371_journalpmed1000050g001-m-300x192.jpg 300w" sizes="auto, (max-width: 349px) 100vw, 349px" />
No matter what you call it — “flush”, “blush” or “glow” — the red face, nausea and rapid heart beat that many people with Asian ancestry experience when they drink alcohol is more than just a quirk of nature.   Research shows it’s a significant risk factor for esophageal cancer, one of the deadliest malignancies in the world.
In a paper published online yesterday in <a href="https://dx.doi.org/10.1371/journal.pmed.1000050" target="_blank" rel="noopener noreferrer">PLoS Medicine</a>, researchers from the National Institute on Alcohol Abuse and Alcoholism and Japan’s Kurihama Alcohol Center advise physicians that they need to ask their Asian patients about their experiences with alcohol in order to identify and counsel those who are at the highest risk.
In the body, alcohol is first converted into acetaldehyde, a potentially cancer-causing toxin, and then into a harmless substance called acetate.   An enzyme called ALDH2 is responsible for the crucial detoxifying step.   But a genetic variation known as ALDH2*2, most commonly found in people with Asian ancestry, can render the enzyme unable to convert acetaldehyde into acetate.
Having two copies of the ALDH2*2 variation means a person can’t break acetaldehyde down at all.   Even a tiny amount of alcohol leads to a build up of the toxin and extremely unpleasant side effects, causing most of these people to avoid drinking altogether.
People with just one copy of ALDH2*2 flush when they drink alcohol too, but their bodies are able to process some acetaldehyde and their reactions are less severe.   Some of these people build up a tolerance to acetaldehyde, allowing them to drink in substantial quantities. But while these people may think they’ve learned to deal with the annoyance of <a href="https://www.23andme.com/topics/wellness/alcohol-flush-reaction">alcohol flushing</a>, what they’ve really done is train themselves to ignore their bodies’ warning signals.
According to the authors, evidence from several studies has consistently linked alcohol consumption with the risk of esophageal cancer in people with one copy of ALDH2*2.   Depending on the study, the odds of esophageal cancer are raised 3.7 to 18.1 times after taking into account the level of alcohol consumption.   For heavy drinkers with one copy of ALDH2*2 the news is even worse: most studies show their odds of esophageal cancer are increased at least 10-fold.
(23andMe customers can see their data for ALDH2 and learn more about alcohol flushing in the trait report found here.   Customers can also check their data at rs671 using the Browse Raw Data feature.   Each A is a copy of ALDH2*2.)
The authors say that doctors should routinely question Asian patients about their reactions to alcohol and advise those who do flush to keep their drinking to a minimum.   This simple step could have a real impact on esophageal cancer rates.
For example, the authors calculate that if Japanese males with one copy of ALDH2*2 who are moderate to heavy drinkers could be convinced to scale back to only light drinking, 53% of esophageal cancers in this population could be prevented.
“In view of the approximately 540 million ALDH2-deficient individuals in the world, many of whom now live in Western societies, even a small percent reduction in alcohol drinking would translate into a substantial number of lives saved,” the authors write.
Photo: doi:10.1371/journal.pmed.1000050.g001. From: Brooks PJ,  Enoch MA,  Goldman D,  Li TK,  Yokoyama A PLoS Medicine Vol. 6, No. 3, e50 doi:10.1371/journal.pmed.1000050

Researchers Warn That Physicians Need To Ask About Alcohol “Flushing” To Reduce Esophageal Cancer Risk

<img loading="lazy" decoding="async" class="alignright size-full wp-image-3161" title="qt" src="https://blog-api.23andme.com/wp-content/uploads/2009/03/qt.png" alt="" width="322" height="317" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/03/qt.png 608w, https://blogcms.23andme.com/wp-content/uploads/2009/03/qt-300x296.png 300w" sizes="auto, (max-width: 322px) 100vw, 322px" />
Each beat of your heart is the result of a highly coordinated electrical system.   An impulse that starts in a few tiny cells spreads throughout the whole organ, causing cardiac cells to contract, pumping your blood in the never-ending circuit that courses through your body.
The “QT interval”, a measurement made from electrocardiogram recordings of the heart’s electrical activity, reflects the amount of time it takes for cells to reset after a contraction.   If this interval is abnormally long or short, it can scramble the electrical system of the heart, causing an erratic beat and limiting the heart’s ability to supply the body with enough newly oxygenated blood.   This can lead to fainting and, in some cases, sudden cardiac death.
Several genetic mutations that cause long and short QT intervals are known to run in families.   But these mutations don’t account for all cases of sudden cardiac death, nor do they explain the normal variation in QT interval seen in the population.   To learn more about the genetics of heartbeat regulation, two independent research teams (<a href="https://dx.doi.org/10.1038/ng.364" target="_blank" rel="noopener noreferrer">QTGEN</a> and <a href="https://dx.doi.org/10.1038/ng.362" target="_blank" rel="noopener noreferrer">QTSCD</a>) looked for genetic variants associated with natural variation in QT interval in more than 28,000 people.   The results, published online yesterday in the journal Nature Genetics, identify a total of 14 SNPs that can now be used as the basis of future research aimed at understanding susceptibility to QT interval-related irregular heart beat and sudden cardiac death.
“The reason people die from this cardiovascular disorder is because we know nothing about the antecedents,” said Aravinda Chakravarti, QTSCD study senior investigator, in a statement.   “It’s like a truck barreling down a slope: there’s no way to stop it.   The only way out is to understand the science of this in a deep, meaningful way.   If we know, we can begin to intervene.”
More than half of the variants identified by the researchers are located in genes already known to be involved in heart cell regulation, some of which are also mutated in familial syndromes characterized by long QT intervals.   But five of the SNPs are in genes not previously recognized as players in the electrical activity of the heart.   These findings open up new avenues for cardiovascular research.
According to the authors of one study (QTGEN), the variants found in these studies together explain more of the variation in QT interval seen in the population than any other factor except for heart rate.   But they warn that more research is still needed to determine whether the variants actually contribute to the risk for sudden cardiac death in addition to lengthening QT intervals.

Researchers Identify Genetic Variants Linked To Heart Rhythm And Possibly Sudden Cardiac Death

<img loading="lazy" decoding="async" class="alignright size-full wp-image-3145" title="lungs" src="https://blog-api.23andme.com/wp-content/uploads/2009/03/lungs.jpg" alt="" width="302" height="224" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/03/lungs.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2009/03/lungs-300x223.jpg 300w" sizes="auto, (max-width: 302px) 100vw, 302px" />A new discovery could someday help identify smokers at risk for chronic obstructive pulmonary disease (<a href="http://www.nhlbi.nih.gov/health/public/lung/copd/index.htm" target="_blank" rel="noopener noreferrer">COPD</a>), the fourth leading cause of death in the United States.
More than 12 million people in the U.S. have been diagnosed with COPD, and another 12 million may have the condition and not know it.   These people have difficulty breathing due to excessive inflammation in their lungs that has narrowed their airways.  
The cause of the inflammation is usually prolonged exposure to an inhaled irritant, most often cigarette smoke. Nine out of ten COPD deaths can be attributed to smoking.
<h6>Links with COPD, Smoking and Lung Cancer</h6>
But even though most people with COPD are current or former smokers, not every smoker gets COPD.   Only about 20% will develop the disease, suggesting that there might be genetic factors that make some smokers more susceptible than others.
New research, published yesterday in the journal <a href="https://dx.doi.org/10.1371/journal.pgen.1000421" target="_blank" rel="noopener noreferrer">PLoS Genetics</a>, suggests that variation in a genetic region on chromosome 15 previously linked to nicotine addiction, lung cancer, and peripheral artery disease might also increase the risk for COPD.   In light of the mounting evidence for the importance of this stretch of DNA, the authors of the new report suggest that genetic screening of smokers in order to find those at the highest risk may be an attractive interventional strategy.
<h6>Variants Identified</h6>
Sreekumar Pillai, a scientist at GlaxoSmithKline, and colleagues from several research institutions studied a total of more than 5,000 people with European ancestry and found that a SNP on chromosome 15 increased odds of COPD by about 1.3 times.   They also found another SNP increased the odds of COPD by about 1.4 times. The two SNPs are very close to each other and probably both mark the same variation affecting COPD risk, although the authors did not test this.
Research has shown that in smokers, each one of the variants is also associated with smoking one more cigarette per day.   Whether is linked to lung cancer and peripheral artery disease because of or in addition to its effects on smoking has been controversial.   
The authors of the current study say that while their data does not allow them to solve this dilemma with regard to the effects of the chromosome 15 SNPs on COPD, several aspects of their study indicate that the genetic variation has a direct effect on the disease, independent of smoking behavior.
<h6>Lung Function</h6>
The authors do note, however, that in some subsets of their study population the effect of the riskier versions of the genetic variations was greater in current smokers compared to former smokers.   This could mean that people who have a harder time quitting are more likely to develop COPD.   Alternatively, it could be the case that some people are at higher risk for COPD if they continue to smoke.
The researchers also found evidence for variations contributing to COPD on chromosome 4, although the results were not statistically significant. However, this same region of DNA was correlated with lung function in a <a href="https://dx.doi.org/doi:10.1371/journal.pgen.1000429" target="_blank" rel="noopener noreferrer">different report in same issue of PLoS Genetics</a>.   Both research groups pointed out that the nearest gene to the chromosome 4 variations they identified is involved in lung development, suggesting that future research targeting these variations might reveal more insight into COPD and other lung diseases.

Variants Linked to Lung Cancer Might Also Raise Risk for COPD

<img loading="lazy" decoding="async" class="alignright size-full wp-image-3133" title="parkinsonsdisease" src="https://blog-api.23andme.com/wp-content/uploads/2009/03/parkinsonsdisease.jpg" alt="" width="260" height="236" />PET scans showing dopamine activity in a normal brain and a Parkinson&#8217;s patient&#8217;s before and after treatment with a therapeutic implant.
More than a million Americans have Parkinson&#8217;s disease, and another 50,000 are diagnosed each year. Scientists know that many of the characteristic symptoms of Parkinson&#8217;s – tremors, rigid muscles and movement problems – can be traced back to the loss of dopamine-producing brain cells.
But what researchers don&#8217;t fully understand is why these cells are damaged in the first place. There are no clear environmental triggers for Parkinson&#8217;s, and in most people with the disease genetics doesn&#8217;t seem to play a large role either. It could even be that Parkinson&#8217;s is really a number of different diseases, all of which lead to the same end result.
Previous research has ruled out genetics as a major contributor to Parkinson&#8217;s risk; it is estimated to play a role in fewer than 10% of cases. But piecing together the genetics of Parkinson&#8217;s is an active and promising field, because what scientists learn from that minority of cases could improve their understanding of the disease generally. The holy grail would be to pin down all the ways genes can interact with the environment to produce the symptoms of Parkinson&#8217;s.

23andMe is working with the <a href="http://www.michaeljfox.org/" target="_blank" rel="noopener">Michael J. Fox Foundation</a>, the <a href="http://www.thepi.org/" target="_blank" rel="noopener">Parkinson&#8217;s Institute</a> and patients from around the world partly because we want to give individuals with Parkinson&#8217;s access to their own genetic data. At the same time, we want to join the continuing quest for those genetic and environmental factors that underlie Parkinson&#8217;s disease by combining genetic data from our community with members&#8217; responses to surveys about their health.
By far the most common known genetic cause of Parkinson&#8217;s disease is the G2019S mutation, which occurs in a gene called LRRK2. While the average person has a 1-2% chance of developing Parkinson’s, the risk for someone with the G2019S mutation is much higher and increases with age. One recent study found that a person who inherits this mutation from either parent has a 28% chance of developing Parkinson’s by the age of 59, 51% by the age of 69 and 74% by the age of 79.
Even though it is the most common known genetic cause of Parkinson&#8217;s disease, the G2019S mutation is responsible for only a small fraction of all cases worldwide – about one or two in a hundred. But in some ethnic groups it is a much more frequent cause of the condition. According to published research, up to 40% of people of North African Arab ancestry and 20% of Ashkenazi Jewish people with Parkinson’s have this mutation.
Another mutation in the LRRK2 gene, referred to as G2385R, has been associated with Parkinson&#8217;s disease in several East Asian populations. Analyses of the combined results from several studies indicate that people who inherit this mutation from either parent are at two to three times greater odds of developing Parkinson&#8217;s than those who do not carry the mutation. Approximately 9% of Parkinson&#8217;s patients with Asian ancestry carry the G2385R mutation.
(23andMe customers can find out if they carry the LRRK2 G2019S mutation in the Parkinson&#8217;s Disease Clinical Report. Customers can also find out if they carry the G2385R mutation using the Parkinson&#8217;s Disease: Preliminary Research Report.)
Although people who have at least one copy of the LRRK2 G2019S or G2385R mutation have an increased risk of Parkinson’s disease, a substantial proportion of people with these mutations never develop the disease. Very little is known about the function of the protein made by the LRRK2 gene, and no one knows why many people who carry mutations in this gene don’t develop Parkinson’s disease. Adding to the mystery, among those with these mutations who do develop Parkinson&#8217;s, not all have the same symptoms. Interactions of these mutations with unknown environmental factors may be part of the explanation. Continuing research into these gene-environment interactions could yield valuable clues into the causes of Parkinson&#8217;s generally.
Mutations in several other genes have also been associated with Parkinson’s disease, but these are extremely rare. Many have been found only in one or two families. 23andMe is not able to detect most of these rare mutations.
Other Parkinson’s mutations:
<ul>
<li>As is the case for mutations in LRRK2, a person need only inherit a mutation in the alpha-synuclein gene (SNCA, also known as PARK1 or PARK4) from one parent to be at substantial risk for Parkinson&#8217;s disease. The average age for disease onset in people with a disease-causing mutation in this gene is 46. The protein encoded by the alpha-synuclein gene is one of the main components of the protein aggregates found in brain cells of people with Parkinson&#8217;s disease.</li>
<li>Mutations in parkin (PARK2), PINK1 (PARK6) and DJ1 (PARK7) are recessive, which means a person must inherit mutated copies of these genes from both parents in order to develop Parkinson&#8217;s (there are rare exceptions). Multiple mutations in each of these genes have been identified; some are extremely rare.</li>
<li>Parkinson&#8217;s disease caused by mutations in parkin, PINK1 or DJ1 usually strikes at a young age. Parkin mutations most often lead to disease onset between the ages of 20 and 40, although some people are younger than 10 or older than 60 when they develop symptoms. PINK1 mutations usually cause Parkinson&#8217;s between the ages of 32 and 48. DJ1 mutations are associated with an age of onset between 20 and 40 years of age.</li>
</ul>
This is an exciting time in the history of Parkinson&#8217;s research. The genetic aspects of the disease could reveal information that is invaluable in the ongoing search for new treatments, or even a cure. We invite Parkinson&#8217;s patients, their families and friends, and anyone who believes in the power of scientific research to change lives to participate in the 23andMe Parkinson&#8217;s disease community. Visit the 23andMe Parkinson&#8217;s community page to learn more.

Understanding The Genetics of Parkinson’s Disease: A Work In Progress

<img loading="lazy" decoding="async" class="alignright wp-image-3125 size-full" title="nycpeeps2" src="http://35.88.189.111/wp-content/uploads/2009/03/nycpeeps2.jpg" alt="People on a city street waiting to cross." width="453" height="273" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/03/nycpeeps2.jpg 453w, https://blogcms.23andme.com/wp-content/uploads/2009/03/nycpeeps2-300x181.jpg 300w" sizes="auto, (max-width: 453px) 100vw, 453px" />
Before 500 years ago people rarely went far to find a mate, choosing a husband or wife from the locally available pool of men and women. But with the dawn of European colonialism people from different parts of the world were suddenly living side by side, and had a whole new set of people to choose from when picking a mate. This trend continues especially in today&#8217;s world, where education and work opportunities have flung young people across the globe, allowing them to interact &#8211; and potentially marry &#8211; people from opposite sides of the globe.
There is ample historical evidence for an increase in exogamy (that is, marrying someone outside your village or town) over the past few hundred years, but could there be evidence stored in our genes as well?   In this week&#8217;s <a href="http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1000415" target="_blank" rel="noopener">PLoS Genetics</a>, an international team of scientists claims to have found genetic clues that allow them to see decreases in inbreeding across the 20th century.

Every person has two copies of each gene – one from our mother and the other from our father.   The more closely related a person&#8217;s parents are, the more similar those two copies are to one another.
The authors of the PLoS Genetics study examined the DNA of more than 800 Americans of European ancestry who ranged in age from 19 to 99. Then they looked at how closely each person&#8217;s two DNA strands matched one another, a measure called autozygosity that roughly corresponds to the amount of inbreeding in an individual&#8217;s pedigree.
The results overwhelmingly confirmed the notion that levels of autozygosity have significantly decreased over time.   When the authors examined the DNA of the youngest subjects, they found significantly lower levels of autozygosity when compared to the oldest subjects.   In fact, they found a steady decrease in levels as they went from oldest to youngest.
What does this mean?   In the last several generations, there&#8217;s been a steady decrease in marrying someone from the same town, village, or region (who could potentially be a distant relative).   Instead, the percentage of people who&#8217;ve chosen to marry someone from a different town, village, region, or even continent, has been on the rise.
According to the authors there are benefits to this increase in genetic diversity, primarily a reduction in the risk of recessive genetic diseases.

Latest Posts — Page 194