<img loading="lazy" decoding="async" class="alignright size-full wp-image-16736" title="CoryMclean" src="https://blog-api.23andme.com/wp-content/uploads/2012/11/CoryMclean.jpg" alt="" width="130" height="170">
(Editor&#8217;s note: Here is a <a href="https://blog-api.23andme.com/wp-content/uploads/2012/11/LRRK2_ASHG2012_cmclean_poster.pdf" target="_blank" rel="noopener noreferrer">link</a> to Cory&#8217;s poster presented at ASHG.)
Parkinson’s disease (PD) research has long been a priority at 23andMe. Our <a href="https://www.23andme.com/pd/" target="_blank" rel="noopener noreferrer">Parkinson’s research communit</a>y is one of the largest in the world with over 9,300 patients. &nbsp;Our <a href="https://www.23andme.com/about/press/pd_discoveries_plos_62311/" target="_blank" rel="noopener noreferrer">research</a> on the disease has been published in peer-reviewed journals. &nbsp;And our scientific contributions have received wide acclaim with generous help from the <a href="https://www.michaeljfox.org/" target="_blank" rel="noopener noreferrer">Michael J. Fox Foundation</a>, <a href="https://www.youtube.com/watch?feature=player_embedded&amp;v=9B9cgyEeULU" target="_blank" rel="noopener noreferrer">Muhammad Ali</a>, and many others. Given our dedication to and reputation for Parkinson’s research, it isn’t surprising that this disease is also the subject of our first whole-genome sequencing project.
Genotyping and whole-genome sequencing are two very different ways of approaching genetic data; one of the primary differences is that genotyping only looks at a subset of locations in your DNA whereas sequencing looks at every location. &nbsp;Sequencing, thus, generates a lot more data. &nbsp;23andMe’s Personal Genome Service ® is currently based only on genotyping but the company has been exploring sequencing as the costs of the technology have dropped.
23andMe’s first whole-genome sequencing project sequenced 50 customers who agreed to be a part of this research study. Each one of these customers has a mutation called G2019S in the LRRK2 gene that is associated with much higher risk for Parkinson’s disease. But not everyone with this mutation develops Parkinson’s.
Cory McLean, a computational biologist at 23andMe, is using sequence data from these 50 customers to try to discover why. 

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You, too, can contribute to research! How? One easy way is to answer the research <a href="https://www.23andme.com/you/23andwe/surveys/" target="_blank" rel="noopener noreferrer">surveys</a> at 23andMe.
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Of the 50 people with the G2019S mutation studied, 37 have Parkinson’s and 13 do not. Cory has compared the genetic sequence data of those affected and those unaffected in hopes of finding genetic differences between the two groups that help explain why some have developed Parkinson’s while others haven’t. The study also confirms that it is possible to generate accurate whole-genome sequencing data from saliva samples (rather than blood).
Cory will present some of his initial findings in a poster at the<a href="http://www.ashg.org/" target="_blank" rel="noopener noreferrer"> annual meeting of the American Society of Human Genetics</a> (ASHG) on November 7. The hope is that this genetic data will open up new avenues for Parkinson’s research.

23andMe Blog

23andMe Blog Team

Whole-Genome Sequencing of Parkinson’s Patients

<img loading="lazy" decoding="async" class="alignright wp-image-4013 size-full" title="geneticresearch7" src="http://35.88.189.111/wp-content/uploads/2009/07/geneticresearch7.jpg" alt="" width="350" height="268" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/07/geneticresearch7.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2009/07/geneticresearch7-300x230.jpg 300w" sizes="auto, (max-width: 350px) 100vw, 350px" />
Team 23andMe will again have a strong presence at the annual meeting of the American Society of Human Genetics.
We’ve been at this gathering of geneticists and those interested in human genetics ever since 23andMe launched, but this year with the 62nd annual meeting being held in San Francisco – sort of our backyard – we’ll be there en masse.
Each year the annual meeting attracts the best and brightest in human genetics with thought-provoking displays of research results and stimulating discussions. This year is no different and more than 6,000 people are expected to attend over the four days starting on November 6th.
Along with the 24 scientific sessions – including panel discussions featuring our Senior Director of Research Dr. Joanna Mountain, who will discuss research partnerships between academics and private companies, and Science Content Manager Dr. Shirley Wu, who will speak on the use of social media in research  – there are also 400 presentations drawn from abstracts submitted by scientists from around the world.
This year 23andMe submitted almost two dozen abstracts on a wide range of topics including our groundbreaking and first-ever genome-wide association study on sexual orientation, as well as preliminary findings from our<a href="../announcements/exomes-the-first-of-many/"> Exome Pilot</a>, which is the first exome sequencing offered directly to consumers. (We will link to these abstracts when they’re available on the ASHG website.)
Also reported in one of the abstracts are some of our findings from a full-genome sequencing project on 50 people with the LRRK2 G2019S mutation associated with Parkinson’s disease. We’ll also have details of a study that looks at an association with hypertrophic cardiomyopathy, the leading cause of sudden cardiac death in young athletes.
Being 23andMe we also have some less serious – but no less interesting – abstracts looking at such things as genetic associations with motion sickness, over 250 genetic associations with common traits such as baldness and unibrow, whether DNA can explain why some women get stretchmarks and others don’t, as well as why some people love cilantro and others think it tastes like soap.
We’re pretty excited by the upcoming conference.
We are particularly proud of our colleague, Dr. Uta Francke, who will deliver a presentation as recipient of the 2012 ASHG William Allan Award. As always the gathering will not just be a chance for us to present some of the interesting results from our research, but also to learn from others. There’s some fun stuff too, including a symposium on “Human Genetics in Contemporary Poetry, Fiction, and Art: How Humanists View our World,” and meeting will close with a forward looking symposium on the future of human genetics.
The preliminary 2012 Meeting schedule is now available. While we can’t wait for the meeting, we’re even more excited about sharing some of the interesting findings and breakthroughs we’ve made with the help of our customers. In the coming weeks we’ll collect information on all the 23andMe presentations onto a single web page so you can find them easily.
Stay tuned for more information about 23andMe’s presence at ASHG.
We’ll have a booth in the Exhibit Hall, and knowing our scientists, they’ll manage to squeeze a party in there too.

Highlighting 23andMe Research at ASHG 2012

<img loading="lazy" decoding="async" class="aligncenter wp-image-14448 size-full" title="EMD_Iowa_highres" src="http://35.88.189.111/wp-content/uploads/2012/07/EMD_Iowa_highres.jpg" alt="" width="1978" height="2106" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/07/EMD_Iowa_highres.jpg 1978w, https://blogcms.23andme.com/wp-content/uploads/2012/07/EMD_Iowa_highres-282x300.jpg 282w, https://blogcms.23andme.com/wp-content/uploads/2012/07/EMD_Iowa_highres-768x818.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2012/07/EMD_Iowa_highres-962x1024.jpg 962w, https://blogcms.23andme.com/wp-content/uploads/2012/07/EMD_Iowa_highres-827x880.jpg 827w, https://blogcms.23andme.com/wp-content/uploads/2012/07/EMD_Iowa_highres-1108x1180.jpg 1108w" sizes="auto, (max-width: 1978px) 100vw, 1978px" />23andMe&#8217;s Emily Drabant, PhD, speaking at a Parkinson&#8217;s event in Iowa.
23andMe is tantalizingly close to reaching the goal of enrolling 10,000 patients in our<a href="https://www.23andme.com/pd/"> Parkinson’s research community</a>.
We’re past the 8,000 mark and the pace of enrollment is now more than two-and-a-half times what was a year ago, but we’re not there yet. Getting to 10,000 is important because as any researcher will tell you, there is strength in numbers. Having what is already the world’s largest Parkinson’s community for genetic research helped us discover new genetic variants associated with Parkinson’s – including a potentially protective factor.
While we’ve already dramatically accelerated the pace of Parkinson’s research, we still have much work to do both in better understanding the disease and in finding new treatments.
Later this month, Emily Drabant, PhD, 23andMe’s research manager for our<a href="https://www.23andme.com/pd/"> Parkinson’s community,</a> will speak at the<a href="http://my.clevelandclinic.org/brain_health/default.aspx"> Cleveland Clinic’s Lou Ruvo Center for Brain Health</a> in Las Vegas about 23andMe’s unique patient-centered research model, what we know about the genetics of Parkinson’s and some of the latest advances in Parkinson’s research. The presentation is specifically for patients at the Cleveland Clinic, which is one of our Parkinson’s research collaborators. We’re recruiting 1,000 Parkinson’s patients from the Cleveland Clinic for a sub-study that will integrate clinical data with genetics.
<img loading="lazy" decoding="async" class="aligncenter wp-image-4013 size-full" title="geneticresearch7" src="http://35.88.189.111/wp-content/uploads/2009/07/geneticresearch7.jpg" alt="" width="350" height="268" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/07/geneticresearch7.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2009/07/geneticresearch7-300x230.jpg 300w" sizes="auto, (max-width: 350px) 100vw, 350px" />
Parkinson’s is an extremely complex disease. Uncovering more about the role genetics plays in Parkinson’s could provide valuable information about the development of the disease and how to combat it. Last year 23andMe found<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002141"> two new genetic associations</a> with Parkinson’s and more recently found a genetic variant in the gene SGK1 that is potentially protective against the disease. With the help of the Michael J. Fox Foundation,<a href="http://www.scripps.edu/newsandviews/e_20111031/lograsso.html"> the Scripps Research Institute</a> is following up the SGK1 discovery with lab studies that we hope will lead to new treatments.
We hope to add more breakthroughs as we reach our goal of 10,000 members in the Parkinson’s Research Community.
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Participate in research!<img loading="lazy" decoding="async" class="alignright size-thumbnail wp-image-12404" style="margin-bottom: 10px;" title="Parkinson's disease fight arm" src="https://blog-api.23andme.com/wp-content/uploads/2012/04/pd_fist_300px-150x150.png" alt="" width="125" height="125" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/04/pd_fist_300px-150x150.png 150w, https://blogcms.23andme.com/wp-content/uploads/2012/04/pd_fist_300px-271x271.png 271w" sizes="auto, (max-width: 125px) 100vw, 125px" />
<div>As a member of 23andMe, you can participate in research simply by taking <a href="https://www.23andme.com/you/23andwe/surveys">surveys</a>. If you have Parkinson&#8217;s disease or know someone who does, learn more about joining our <a href="https://www.23andme.com/pd">Parkinson&#8217;s Disease</a> initiative!</div>
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Of course, the success of the 23andMe’s Parkinson’s Community has come with the help of some very active members of the community, including more than 200 Parkinson’s “Ambassadors,” who’ve helped spread the word about the research. 23andMe has also received the support of some great people, Michael J. Fox and Muhammad Ali, who have both lent their efforts to the cause. Finally we’ve been helped by some fantastic partners like the Cleveland Clinic, the<a href="https://www.michaeljfox.org/"> Michael J. Fox Foundation</a>, the<a href="http://www.thepi.org/"> Parkinson’s Institute</a>, the National Parkinson Foundation, the Parkinson’s Association of San Diego, the Cure Parkinson’s Trust and Parkinson’s UK.

23andMe’s Parkinson’s Community is Almost There

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[Ed: A clarifying addendum has been added to the end of this post. &#8211; 6/01/12]
23andMe has a substantial research arm with more than 20 scientists dedicated to making meaningful discoveries that will improve the lives of all of us.  We’ve made a number of discoveries that we’ve <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1000993" target="_blank" rel="noopener noreferrer">published</a> in <a href="http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1002141" target="_blank" rel="noopener noreferrer">peer reviewed journals</a> and on our website.
As we make these discoveries, we have often debated: what is the best way to make sure that genetic breakthroughs translate into real-world benefits?  We want to make discoveries that will impact your life and the lives of everyone on the planet.  We do not want our discoveries to just be an academic pursuit &#8212; we want to meaningfully improve lives.
Our patent, “<a href="http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&amp;Sect2=HITOFF&amp;d=PALL&amp;p=1&amp;u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&amp;r=1&amp;f=G&amp;l=50&amp;s1=8,187,811.PN.&amp;OS=PN/8,187,811&amp;RS=PN/8,187,811">Polymorphisms Associated With Parkinson’s Disease</a>” is expected to issue on Tuesday, May 29, 2012. This relates to our discovery of a variant in the SGK1 gene that may be protective against Parkinson’s disease in individuals who carry the rare risk-associated LRRK2 G2019S mutation.  Our patent is an important step in ensuring that we’ve done all we can towards successful translation of this discovery.  If the follow up work we are now doing with the Scripps Research Institute and the Michael J. Fox Foundation looks promising and moves towards drug development, the patent will be important for a biotech or pharmaceutical company to pursue drug development.
We believe patents should not be used to obstruct research or prevent individuals from knowing what&#8217;s in their genome. We believe that everyone has a right to know their genomes &#8212; their sequence of As, Ts, Cs, and Gs &#8212; and should be able to access them should they want to.  This has been our guiding principle since day one, and 23andMe has pioneered the ability for individuals to have unfettered access to their genomes.
We recognize that patents are complicated and can be controversial. Patents were created to protect innovation. Is discovering the function of a gene an innovation?
The question of whether innovations related to genetics can be patented is in hot debate as evidenced by recent rulings related to <a href="http://www.supremecourt.gov/opinions/11pdf/10-1150.pdf" target="_blank" rel="noopener noreferrer">Prometheus</a> and Myriad patents.
We want to emphasize that we are firm in our belief that individuals should have access to their own genetic data. We will continue to pursue patents that we believe will eventually benefit us all. The majority of our customers have opted to participate in research. Thanks to that community, we have been able to make an incredible number of novel discoveries. We want those discoveries to move from the realm of academic publishing to the world of impacting lives by preventing, treating or curing disease.
Addendum &#8212; June 1, 2012:
The patent announcement has generated a lot of discussion. In addition to reiterating our core beliefs I&#8217;d like to clarify a few points about our perspective:
23andMe will not prevent others from accessing their genetic data or its interpretation specific to our patents.
Other entities can present information about the genetic associations covered in our patents without licensing fees. As has always been the case, 23andMe customers can freely apply their raw genetic data to other interpretation tools whenever they wish.
23andMe is a business with a mission to improve lives.  
We sell a service to our customers and we conduct research, on our own and with partners, that we believe will lead to better treatments, diagnostics, and prevention of disease. We aim for these discoveries to benefit everyone.
Patents give organizations researching and developing new drugs confidence that their significant investments will be commercially viable.  
Developing new drugs and treatments costs time and money. A lot of time and money. Often the only way a company will even think about pursuing a drug lead is if they have assurance that they can recoup their investment. Having patent protection over the entire line of discovery gives a company confidence to invest in this resource-intensive process.
Many of you, <a href="http://blog.michaeljfox.org/2012/05/patent-23andme-step-meaningfully-improving-lives/">especially in the Parkinson&#8217;s community</a>, saw this as a major milestone and the first step in potentially having a meaningful impact on the lives of Parkinson&#8217;s patients. Our ultimate goal is to make discoveries that will benefit everyone.

Announcing 23andMe’s First Patent

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By Nick Eriksson, 23andMe Principal Scientist, and Lizzie Dorfman, Parkinson&#8217;s Research Project Manager
Less than a year ago we announced the <a href="https://www.23andme.com/about/press/20090312/" target="_blank" rel="noopener noreferrer">launch of the 23andMe Parkinson’s Research Initiative</a>. Since then, we have built one of the world&#8217;s most useful resources for studying the <a href="https://blog.23andme.com/2009/03/19/understanding-the-genetics-of-parkinsons-disease-a-work-in-progress/" target="_blank" rel="noopener noreferrer">genetics of Parkinson&#8217;s disease</a>.
This past December we had meetings with the <a href="http://www.nih.gov/" target="_blank" rel="noopener noreferrer">National Institutes of Health</a>, <a href="http://www.fastercures.org/" target="_blank" rel="noopener noreferrer">FasterCures</a>, pharmaceutical companies and several key Parkinson’s geneticists to discuss our research. The feedback was unequivocally positive. We are thrilled by the progress we’ve made and wanted to make sure to publicly share some of our most significant accomplishments to date, as well as a preview of what is to come.
<h6>Progress on Recruitment</h6>
So far, more than 3,500 people with Parkinson&#8217;s disease from 49 U.S. states and 17 countries have submitted saliva samples for genetic analysis and carefully answered more than 30,000 online surveys to help with our research. Our genetic database now includes many important subgroups of Parkinson&#8217;s patients, each presenting a tremendous opportunity for current and future research.
These include a large group of people with early-onset Parkinson’s (â‰¤50 years old at diagnosis), carriers of extremely rare mutations that are known to strongly predispose a person for the disease, and people with a family history of Parkinson&#8217;s with no known cause. We&#8217;ve also had an incredible response from our other communities: more than 8,000 people without Parkinson&#8217;s have taken our Parkinson’s surveys so that they can be included in our studies as crucial control subjects.
<h6>Unique Research Model</h6>
An important aspect of research at 23andMe, one that distinguishes us from many other research programs, is the way we collect information about the health, activities and environment of our participants.   Traditional methods of data collection &#8212; for example, using an existing medical record or a meeting between a researcher and each participant &#8212; can be costly, time-consuming and limit the number of people willing and able to participate.
In contrast, 23andMe utilizes simple online surveys that can be completed anywhere at anytime.   This allows people from all over the world to easily participate in our research on an on-going basis. Because this is a new way of collecting data, we&#8217;ve taken special care to make sure that the information we collect is accurate.   Careful analysis has indicated that the survey answers our participants have been providing are of very high quality.
<h6>How can we tell?</h6>
Well, one example is that we&#8217;ve independently identified many of the same genetic markers previously found by other Parkinson&#8217;s researchers.   Even the magnitude of the effects we&#8217;ve found are similar to what other research groups have seen.
For example, the <a href="https://blog.23andme.com/2009/11/17/snpwatch-common-genetic-variants-associated-with-risk-for-parkinsons-disease-identified-in-asian-and-european-populations/" target="_blank" rel="noopener noreferrer">published literature</a> has shown that each copy of a G at SNP rs393152 near the MAPT gene reduces the odds of Parkinson&#8217;s by 0.23 times. This is very similar to what we&#8217;ve seen in our data: we found that each G reduced the odds of Parkinson&#8217;s by 0.21 times. Each G at rs2736990 near the SNCA gene has been shown to increase the odds of Parkinson&#8217;s by 1.23 times. We found an increase of 1.28 times for each G .
In addition, we&#8217;ve also replicated the known associations between the LRRK2 and <a href="https://www.ncbi.nlm.nih.gov/sites/entrez?cmd=Search&amp;db=pubmed&amp;term=19846850" target="_blank" rel="noopener noreferrer">GBA</a> genes and Parkinson&#8217;s. All of these results are important and exciting evidence that our revolutionary new way of conducting research is a viable alternative to traditional methods.
<h6>Verifying Other Findings</h6>
Thanks to the detailed information that has been contributed by everyone participating in the 23andMe Parkinson&#8217;s community, we&#8217;ve also been able to verify some things about Parkinson&#8217;s that aren&#8217;t genetic. For example, we see that <a href="https://www.23andme.com/health/Parkinsons-Disease/" target="_blank" rel="noopener noreferrer">LRRK2 G2019S</a> carriers who have Parkinson&#8217;s disease show fewer symptoms than other patients when adjusted for duration of the disease, age of onset, and sex.
This is similar to the result in a paper published by other researchers in the journal <a href="https://www.ncbi.nlm.nih.gov/pubmed/18539534" target="_blank" rel="noopener noreferrer">Lancet Neurology</a> in 2008. The survey answers we&#8217;ve collected are also able to divide our participants into the classically observed   tremor dominant and postural instability gait difficulty (PIGD) subtypes of Parkinson&#8217;s. These and other similar results provide further support for our web-based paradigm for conducting clinical research.
<h6>Collaborators</h6>
We are currently working with the <a href="http://www.thepi.org/" target="_blank" rel="noopener noreferrer">Parkinson&#8217;s Institute</a>, with funding from the <a href="http://www.michaeljfox.org/" target="_blank" rel="noopener noreferrer">Michael J. Fox Foundation</a>, on a <a href="https://www.23andme.com/about/press/20080514/" target="_blank" rel="noopener noreferrer">long term project</a> to formally show that Parkinson&#8217;s disease data collected online is as good as data collected in a clinical setting.
We&#8217;re very excited about the possibilities of the data we&#8217;ve collected from the Parkinson&#8217;s Disease Research Initiative. We&#8217;re in the process of writing up some of the results we&#8217;ve shared here, along with some others, and will soon submit papers on Parkinson&#8217;s Disease genetics to peer-reviewed scientific journals.
Also in store for the year ahead: continued recruitment, new research surveys, cutting-edge and exploratory data analysis techniques and new research collaborations. We&#8217;ll be sure to keep sharing our progress.
We would also like to express our thanks for the support and outreach efforts of several organizations. Since our launch we&#8217;ve been honored to work with the Michael J. Fox Foundation and The Parkinson&#8217;s Institute and Clinical Center. Over the last year we have been thrilled to add the support of <a href="http://www.parkinson.org" target="_blank" rel="noopener noreferrer">The National Parkinson Foundation</a>, <a href="http://www.patientslikeme.com/" target="_blank" rel="noopener noreferrer">PatientsLikeMe</a>, <a href="http://www.nwpf.org/" target="_blank" rel="noopener noreferrer">The Northwest Parkinson&#8217;s Foundation</a> and <a href="http://www.cureparkinsons.org.uk/" target="_blank" rel="noopener noreferrer">The Cure Parkinson&#8217;s Trust</a>, among others.
Speaking of outreach, it&#8217;s not too late to join in our efforts and help us make even more discoveries.   If you have been diagnosed with Parkinson&#8217;s disease, all it takes to join our research initiative is $25, a small saliva sample and the ability to answer online surveys. Learn more and request a discount code here: <a href="https://www.23andme.com/pd/" target="_blank" rel="noopener noreferrer">https://www.23andme.com/pd/</a>.

Nick Eriksson

23andMe Parkinson’s Research Initiative Progress Update

<img loading="lazy" decoding="async" class="alignright size-full wp-image-5677" title="alzheimers" src="https://blog-api.23andme.com/wp-content/uploads/2009/12/alzheimers.jpg" alt="alzheimers" width="357" height="254" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/12/alzheimers.jpg 435w, https://blogcms.23andme.com/wp-content/uploads/2009/12/alzheimers-300x214.jpg 300w" sizes="auto, (max-width: 357px) 100vw, 357px" />
More than a million Americans have Parkinson’s disease, and another 50,000 are diagnosed each year. There is active research to try to understand this devastating condition, but scientists still don&#8217;t really know what causes it.   There are no clear environmental triggers for the disease, and genetics doesn’t seem to play a large role either — it is estimated to be involved in fewer than 10% of cases.
Of the <a href="https://blog.23andme.com/2009/03/19/understanding-the-genetics-of-parkinsons-disease-a-work-in-progress/" target="_blank" rel="noopener">few known genetic causes of Parkinson&#8217;s</a>, one of the most common is the LRRK2 G2019S mutation. 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.
Previous research had suggested that the LRRK2 G2019S mutation is associated with a form of Parkinson&#8217;s where the predominant symptom is tremor.   But a new study, published this week in the <a href="http://archneur.ama-assn.org/cgi/content/abstract/66/12/1517?maxtoshow=&amp;HITS=10&amp;hits=10&amp;RESULTFORMAT=&amp;fulltext=motor+phenotype&amp;searchid=1&amp;FIRSTINDEX=0&amp;resourcetype=HWCIT" target="_blank" rel="noopener">Archives of Neurology</a>, suggests that carriers of this mutation are in fact more likely to manifest a different form of Parkinson&#8217;s called the postural instability and gait difficulty (PIGD) phenotype.    Though this result must be borne out by further studies, it could have important implications for what mutation carriers can expect from their disease: the <a href="http://www.pdonlineresearch.org/responses/3614/289/clinical-pd-subtypes-tremor-dominant-and-postural-instability-gait-difficulty-pig" target="_blank" rel="noopener">PIGD phenotype</a> of Parkinson&#8217;s is associated with a less favorable prognosis.
Dr. Roy Alcalay and colleagues analyzed the DNA of 691 people with early-onset Parkinson&#8217;s disease (symptoms starting before age 51) from13 movement disorder centers throughout the United States, 26 of whom carried the LRRK2 G2019S mutation.   Patients were scored for various measures of tremor and the PIGD phenotype using the Unified Parkinson&#8217;s Disease Rating Scale (UPDRS).   A ratio of the two scores was then used to assign a designation as tremor dominant, PIGD, or intermediate.   Earlier studies of LRRK2 G2019S carriers did not employ this careful scoring system.
After adjusting for Ashkenazi Jewish ancestry (the G2019S mutation is especially common in this group) and disease duration, Alcalay et al. found that mutation carriers were more likely than non-carriers to have the PIGD phenotype.   Due to the small sample size it&#8217;s hard to say precisely how large the effect was, but the researchers estimate an increase in odds of 17.7 times, although the true increase may fall anywhere between 3.8 and 83.1 times.
In general, studies have indicated that the people with Parkinson&#8217;s who have the PIGD phenotype have more severe disease and faster cognitive decline than patients with tremor dominant disease.   Whether this prognosis applies to LRRK2 G2019S carriers with the PIGD phenotype remains to be tested.
More work with larger and more ethnically diverse study samples that are followed for a longer period of time will be needed to confirm these findings.
Even though it is the most common known genetic cause of Parkinson’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.

LRRK2 Implications for Parkinson’s Disease

<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="parkinsonsdisease" width="260" height="236" />PET scans showing dopamine activity in a normal brain and a Parkinson’s patient’s before and after treatment with a therapeutic implant. 
More than a million Americans have Parkinson’s disease, and another 50,000 are diagnosed each year.
Scientists know that many of Parkinson’s’s characteristic symptoms—tremors, rigid muscles, and movement problems—can be traced back to the loss of dopamine-producing brain cells. But what researchers don’t fully understand is why these cells are damaged in the first place.
<h2>Genetics and Other Factors</h2>
For most cases of Parkinson&#8217;s, the brain cell damage is probably the result of complex interactions between<a href="https://blog.23andme.com/2009/03/19/understanding-the-genetics-of-parkinsons-disease-a-work-in-progress/" target="_blank" rel="noopener noreferrer"> multiple genetic and environmental factors</a>.   Despite years of work, however, hardly any of these factors are known.   But now two research groups have identified several genetic variants associated with the risk of Parkinson&#8217;s in Asian and Caucasian populations.   Their results were published online this week in the journal Nature Genetics.
One group, led by <a href="https://dx.doi.org/10.1038/ng.485" target="_blank" rel="noopener noreferrer">Wataru Satake</a>, analyzed the DNA of 2,011 Japanese people with Parkinson&#8217;s disease and 18,381 controls.   The other group, composed of U.S. and German researchers (<a href="https://dx.doi.org/10.1038/ng.487" target="_blank" rel="noopener noreferrer">SimÃ³n-SÃ¡nchez et al.</a>), looked at the genetics of 5,074 Caucasians with Parkinson&#8217;s and 8,551 without the disease.
<h2>Common Genetic Variants</h2>
Common variations in and around two genes previously associated with rare familial forms of Parkinson&#8217;s disease, SNCA, and LRRK2, were associated with the risk for Parkinson&#8217;s in the Japanese study.   In the Caucasian study, the association with SNCA was strong, but the evidence for an association between Parkinson&#8217;s and common variation near LRRK2 was only suggestive.   Given that the association of mutations in this gene with familial forms of Parkinson&#8217;s is so strong, SimÃ³n-SÃ¡nchez et al. nevertheless think there truly is a role for SNPs near this gene in non-familial forms of the disease.
Satake et al. also found that variations in a region of the genome not previously linked to Parkinson&#8217;s disease could affect the risk for the disease.   This region of chromosome 1 contains several genes, and it is unclear which one might be involved in Parkinson&#8217;s.   Satake et al. named the region PARK16.   After comparing their data, the U.S./German group also found a link between Parkinson&#8217;s disease and the PARK16 region.
A SNP in the BST1 gene was associated with increased risk for Parkinson&#8217;s in the Japanese sample, but did not show any link to the disease in the Caucasian sample.   The risk version of this SNP, however, is found at very low levels in Caucasians.   This may have been why SimÃ³n-SÃ¡nchez et al. were unable to pick it up in their analysis.
<h2>The MAPT Gene</h2>
Finally, a SNP in the MAPT gene, which has also been associated with familial forms of Parkinson&#8217;s, was associated with disease risk in the Caucasian sample but not in the Japanese.
Work to find common genetic variations affecting the risk for Parkinson&#8217;s will no doubt continue as researchers try to identify all of the puzzle pieces relevant to this devastating disease and how they fit together.
&#8220;A further increase in the number and size of cohorts for [genomewide association studies] in [Parkinson&#8217;s disease] will likely reveal additional common genetic risk loci, and these, in turn, will improve understanding and, ultimately, treatment of this devastating disorder,&#8221; concludes SimÃ³n-SÃ¡nchez et al.
Although variations in some of the same genes were found in both the Caucasian and Japanese samples, the same SNPs often do not apply to the different populations. People looking up their own data should use the SNPs listed for the ethnicity they identify most closely with.
*Risk version is more standard version of SNP. 
**Results did not meet strict cut offs for statistical significance, but researchers suggest the associations are nonetheless real.

Genetic Variants Associated With Risk for Parkinson’s Disease

<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

LRRK2 — Page 2