<img loading="lazy" decoding="async" class="alignright size-medium wp-image-17362" title="Woman weighing herself on scales in health club" src="https://blog-api.23andme.com/wp-content/uploads/2013/01/womenScale-300x214.jpg" alt="" width="300" height="214" />
There are lots of things we can&#8217;t change, but our lifestyle isn&#8217;t one of them. Good thing, too  – our weight, nutrition habits, and exercise behaviors impact us beyond whether we look good in a swim suit. They also influence our risk for many different diseases.
In the same way, our DNA also contributes to our risk for various diseases. It&#8217;s where our lifestyle and DNA intersect that we have the greatest potential for positive change. For instance, the knowledge that my genes put me at higher-than-average risk for heart disease may make me think twice about the extra slice of bacon (so long as it&#8217;s not within smelling distance!). And going light on the bacon for the long haul may ultimately lower my risk for many conditions besides heart disease.
So where might your genetic incentives be?
<div>Obesity</div>
Extra pounds equate to extra risk for numerous <a href="https://www.23andme.com/dna-health-ancestry/">health conditions</a>. The obese are seven times more likely to develop type 2 diabetes, three times more likely to develop gallstones, and twice as likely to develop coronary heart disease or venous thromboembolism (blood clots) compared to those at a healthy weight.
Each of these obesity-associated conditions has at least one 23andMe genetic report (see the links above).  If you find that your genetics puts you at higher-than-average risk for one of these conditions, perhaps this knowledge will motivate you to keep your weight in check.  To the fortunate few with lower-than-average genetic risk for all the conditions above, don’t grab that donut yet.  Obesity still increases your risk compared to those at a healthy weight, and there are likely many additional genetic factors that are as-of-yet unknown but may contribute to your risk.
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Nutrition 
Poor nutrition, even discounting its effect on your waistline, certainly doesn’t keep the doctor away.  People who consume red meat ten times per week or more have about a 50 percent higher risk for age-related macular degeneration, an eye condition that can lead to blindness. Furthermore, studies suggest that a diet high in fiber, vegetables, nuts, and foods typically found in Mediterranean cuisine is associated with 20-40 percent lower risk for coronary heart disease. Colorectal cancer is also linked with poor diet habits, and experts suggest that  diets high in fiber and low in fat can lower your risk.
If you find that you are at increased genetic risk, this knowledge may help you prioritize which dietary changes to make. For example, a person who has a strong genetic risk for age-related macular degeneration might consider eating more fish, nuts, and leafy greens  – foods linked to lower risk for that disease.
Exercise 
A gym membership (if actually used) may positively impact your health. For starters, exercise helps keep one’s weight in check; people who exercise regularly are up to 60 percent less likely to be overweight than people who don&#8217;t exercise.
Even beyond that, exercise can strengthen one of your most important muscles: your heart. People who don&#8217;t exercise are about twice as likely to develop coronary heart disease as people who exercise regularly. In women, walking just an hour a week is associated with 50 percent lower risk for coronary heart disease and in men, vigorous activity and playing sports may lower the risk for heart disease.   If your genetics suggest you&#8217;re at higher than average risk for heart disease, take that as extra incentive to hit the gym regularly!
Poor exercise also influences your risk for type 2 diabetes.   People who engage in moderate physical activity on a regular basis or simply walk for at least two and a half hours a week at a brisk pace are about 30 percent less likely to develop type 2 diabetes compared to people who don&#8217;t exercise.   If your genetic report shows you are already at higher than average risk for type 2 diabetes, perhaps you may want to go the extra mile to make a change.
The Competitive Advantage 
Unfortunately, health isn&#8217;t an even playing field. Just as some people have genetic variants associated with lower than average risk for disease, some are born with skinny genes (and can wear skinny jeans).
<div>Still, there are other genetic factors that may help in the battle of the bulge. One that&#8217;s received a lot of attention is in a gene called PPARG. Normally, high fat intake is associated with weight gain, but in people with a certain variation of the PPARG gene, a diet high in monounsaturated fat is actually linked to weight loss. Monounsaturated fat is found in olive oil, so this type of diet has been nicknamed the &#8220;Mediterranean&#8221;-style diet.</div>
Very few genetic factors have been reliably linked to diet and exercise but some of the preliminary findings..
Whatever your health goals may be, we wish you success that outlasts the month.  May this knowledge about your DNA  – whether that be the genetics of disease risk or the genetics of losing weight  – help you towards a fitter you.

23andMe Blog

23andMe Blog Team

Your Lifestyle, Your Health, Your Genes

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You may lack the enzyme thiopurine methyltransferase (TPMT) and not even know it.



<h6 class="wp-block-heading" id="h-serious-side-effects">Serious Side Effects</h6>



<figure class="wp-block-image alignright size-medium"><img loading="lazy" decoding="async" width="300" height="285" src="http://35.88.189.111/wp-content/uploads/2010/11/cartoon-pills-300x285.png" alt="An image of prescription bottles. " class="wp-image-7843" srcset="https://blogcms.23andme.com/wp-content/uploads/2010/11/cartoon-pills-300x285.png 300w, https://blogcms.23andme.com/wp-content/uploads/2010/11/cartoon-pills.png 478w" sizes="auto, (max-width: 300px) 100vw, 300px" /><figcaption class="wp-element-caption">Some of the more common thiopurine drugs:
6-Thioguanine (Lanvis ®)
6-Mercaptopurine (Purinethol ®)
Azathioprine (Azasan ®, Imuran ®)</figcaption></figure>



For most of those who lack the enzyme, it will never be a problem, but, for those who are prescribed thiopurine medication, the lack of functional TPMT enzyme could lead to <a href="https://blog.23andme.com/articles/23andme-customers-reported-side-effects-to-drugs">serious side effects</a>.



Thiopurines are a family of drugs that are used to “turn down” or suppress the immune system, which can be useful when you want to reduce inflammation, for instance.



They&#8217;re used in a variety of treatments for such conditions as <a href="https://blog.23andme.com/articles/more-than-100-genetic-variations-associated-with-leukemia-treatment-response">leukemia</a>, organ transplant rejection, rheumatoid arthritis, Crohn&#8217;s disease, and inflammatory bowel disease.



<h6 class="wp-block-heading" id="h-pharmacogenetic-testings">Pharmacogenetic Testings</h6>



While these are important drugs for many individuals, for those who lack functional TPMT enzyme, thiopurines cause serious side effects, such as bleeding and low blood count. &nbsp;Because of these potential side effects, a doctor can test for TPMT enzyme activity before prescribing thiopurine drugs, but a test isn’t always done.



There are a couple of different types of tests available. &nbsp;One type of test looks at the levels of TPMT enzyme directly. &nbsp;Another type of test looks for mutations in the gene that encodes the TPMT enzyme. &nbsp;Approximately 10 percent of people with European ancestry have reduced TPMT activity due to having inherited one mutant TPMT gene. About 0.3 percent have none at all due to having inherited two mutant copies.

Genetics and Response to Thiopurine Medications

<img loading="lazy" decoding="async" class="alignright wp-image-3440 size-medium" title="Abstract DNA" src="http://35.88.189.111/wp-content/uploads/2009/04/istock_000002166527xsmall-300x219.jpg" alt="" width="300" height="219" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/04/istock_000002166527xsmall-300x219.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2009/04/istock_000002166527xsmall.jpg 406w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Earlier this month Public Health Genomics published<a href="http://content.karger.com/ProdukteDB/produkte.asp?Aktion=ShowAbstract&amp;ArtikelNr=343792&amp;Ausgabe=0&amp;ProduktNr=224224"> a paper by a team of Swiss researchers</a> that reinforces the growing body of work showing both a strong consumer interest in DNA testing, and positive experiences with personal genetic testing.
In this study, the participants were life science students at the University of Zurich who purchased the kits from 23andMe at an educational discount. While these participants had more genetic expertise than the average consumer, their responses were not very different from people in other recent studies. 
Many of the respondents described their experience as “fun” and said part of their motivation for getting genotyped was to advance genetic research.
“Their experiences provide valuable insights into the role of personal curiosity and altruism (fostering medical research) as motivations for testing and the utility attributed to both,” the study concludes.
<h6>DNA Testing Does Not Induce Anxiety</h6>
Ninety percent of them described their experience as positive, and a majority indicated the test would impact how they thought about their health.
the study also appears to add more evidence that direct to consumer testing doesn’t induce fear. Although a little more than half the respondents had some concerns about confidentiality and privacy, only one described those as  “serious concerns.”
We’ve written several times about other studies that show people don’t freak out about what they learn from their genetic information. People also say they find value in getting genotyped.
<h6>Motivations for DNA Testing</h6>
This study – the first to look at direct to consumer genetic testing in Europe – shows much the same as previous studies done in the United States. But unlike most of the other studies, it also delves into both why people get genotyped and how they look at that information.
<img loading="lazy" decoding="async" class="aligncenter wp-image-16940 size-medium" title="Motivations for DNA testing for consumers" src="https://blog-api.23andme.com/wp-content/uploads/2012/11/updated-swiss-study-graph-300x181.jpg" alt="" width="300" height="181" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/11/updated-swiss-study-graph-300x181.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2012/11/updated-swiss-study-graph.jpg 362w" sizes="auto, (max-width: 300px) 100vw, 300px" />
In another recent study presented at the annual meeting of the American Society of Human Genetics in San Francisco, Sandra Lee, Ph.D., a Senior Research Scholar at the Stanford Center for Biomedical Ethics, presented findings from a study on 23andMe customers. Most of those in her study freely shared their genetic data with family and friends. Many of them also posted their results on Facebook. This was also the case in the Swiss study, in which about 64 percent of those asked said they’d share their results with family.
Another finding from the Swiss study was that consumers were motivated not just by curiosity but a desire to participate in research in some way.
“23andMe gave them an opportunity they otherwise would not have had to help advance research,” the paper said. “Individual contributions to research were discussed in terms of ‘investments’ in the future. (The) returns being the acceleration of medical discovery and better medicine.”

Consumer Interest in Genetic Testing

<img loading="lazy" decoding="async" class="aligncenter size-medium wp-image-8732" title="DNA-chains" alt="" src="https://blog-api.23andme.com/wp-content/uploads/2011/03/DNA-chains-300x225.jpg" width="300" height="225" srcset="https://blogcms.23andme.com/wp-content/uploads/2011/03/DNA-chains-300x225.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2011/03/DNA-chains.jpg 400w" sizes="auto, (max-width: 300px) 100vw, 300px" />
The story <a href="https://www.nytimes.com/2012/06/07/health/tests-of-parents-are-used-to-map-genes-of-a-fetus.html?pagewanted=all&#038;_r=0">first broke</a> in the summer of 2012 – two separate research groups, one from the University of Washington and the other from Stanford, announced within weeks of each other that they had successfully sequenced a human fetus and done so noninvasively.
Scientist <a href="http://stm.sciencemag.org/content/4/137/137ra76.short">Jacob O Kitzman</a>, who led the University of Washington study, sequenced the fetal genome by analyzing a blood sample from the mother and a saliva sample from the father, while <a href="https://www.nature.com/nature/journal/vaop/ncurrent/full/nature11251.html">H. Christina Fan</a>, leader of the Stanford study, just analyzed a blood sample from the mother.
By sequencing DNA from one or both parents and applying some computational tricks, these researchers were able to decode the genome sequence of the fetus. Their approach was possible because a small but very measurable percentage of DNA found in a pregnant mother’s bloodstream comes from the fetus.
At the ASHG 2012 meeting earlier this month, we heard first hand from Kitzman about their study. When they sequenced the pregnant mother’s plasma (a component of blood) they found that 87 percent of the DNA was of maternal origin and 13 percent was of fetal origin. When they compared their decoded genome to the actual genome of the fetus, which they sequenced using umbilical cord blood collected at birth, their accuracy was around 98 percent for most regions of the genome.
Noninvasive sequencing of human fetuses holds clinical utility. Since the approaches pioneered by Kitzman and Fan don’t rely on <a href="http://www.mayoclinic.com/health/amniocentesis/MY00155">amniocentesis</a> or <a href="http://www.mayoclinic.com/health/chorionic-villus-sampling/MY00154">chorionic villous sampling (CVS)</a> for obtaining fetal DNA, they do not pose a risk to the developing fetus. Both amniocentesis and CVS are invasive procedures that carry a small risk of miscarriage.
Noninvasive fetal sequencing is also clinically useful because it provides a whole genome’s worth of information.
Some might wonder how it’s different from the relatively <a href="https://www.nytimes.com/2011/10/18/business/sequenom-test-for-down-syndrome-raises-hopes-and-questions.html?pagewanted=all">new blood-based screen</a> that some are calling “the Down syndrome test.” This test, already commercially available, only requires a sample of the mother’s blood and is therefore non-invasive. But it differs from fetal sequencing because it only detects large chromosomal abnormalities – for instance having an extra chromosome, which occurs with Down syndrome. In contrast, fetal sequencing detects both chromosomal abnormalities as well as very small mutations like those causing single-gene disorders like cystic fibrosis. Fetal sequencing can also detect <a href="http://ghr.nlm.nih.gov/glossary=denovomutation">“de novo” mutations</a>, changes in DNA that are not inherited from parents but instead occur very early in the course of a person’s life and can also cause disease.
But it’s likely going to take some time before fetal sequencing is actually offered to the general public. The costs need to drop significantly – it’s currently around <a href="https://www.nytimes.com/2012/06/07/health/tests-of-parents-are-used-to-map-genes-of-a-fetus.html?pagewanted=all&#038;_r=0">$20,000-$50,000</a> per fetal genome. More work is also needed to refine the approach and improve the accuracy.
For this study Kitzman drew a blood sample when the fetus was around 18 weeks of gestation, but scientists expect the test to become available for women who are in earlier stages of pregnancy, for instance during the first trimester.
As with traditional prenatal screening such as amniocentesis and chorionic villus sampling (CVS), fetal sequencing can predict a serious medical condition. Fetal sequencing goes further, however, and may enable parents to obtain a rough prediction of traits such as the future eye color of the fetus. If current trends continue, some prospective parents will want such information, while others will prefer to wait until after the baby is born to learn about medical and non-medical conditions. The utility of this test and the decision to use it will depend a great deal on the test’s accuracy, which currently isn’t very high. But it’s clear that testing options for prospective parents will continue to grow in number and complexity.

Noninvasive Sequencing of a Human Fetus

<img loading="lazy" decoding="async" class="aligncenter size-medium wp-image-16865" title="Nick" src="https://blog-api.23andme.com/wp-content/uploads/2012/11/Nick-209x300.jpg" alt="" width="209" height="300" />
You’d be forgiven for assuming your height has nothing to do with the curl of your hair or how flexible you are, but physical traits can sometimes have unexpected connections.
Last week at the annual meeting of the American Society of Human Genetics in San Francisco, 23andMe’s Principal Scientist and Statistical Geneticist Nick Eriksson presented findings from our database about 300 new genetic associations with various physical traits.
It’s not surprising that a single trait – having a<a href="https://www.23andme.com/about/factoids/"> unibrow</a>, for instance – might be influenced by any number of different genetic variants. In the case of unibrow, we’ve found more than 50 genetic variants associated with the trait. It is also well known that genetic variants can be associated with multiple traits and conditions. For example, variants in the PAX3 gene have independent associations with unibrow, whether you’ve got a <a href="https://www.23andme.com/topics/traits/cleft-chin/">chin dimple</a>, or upper back hair.
It’s the sheer volume of newly discovered associations that is so surprising. Beyond that, the work is both interesting and informative in what it says about the web of connections between these traits and conditions. These associations shed new light on how genes and gene expression may influence those conditions and traits as well as certain diseases. 
 
While there may be some novelty in finding associations with traits like breast size, sometimes these associations tell us something very important. In the case of<a href="https://blog-api.23andme.com/wp-content/uploads/2012/11/Genetic-Variants-Associated-with-Breast-Size-and-Cancer.pdf"> breast size</a> there’s a connection with breast cancer, for instance. And these associations can also lead us to new ways of thinking about how certain conditions develop.
Nick’s presentation was meant in part to simply put out there some of the findings we’ve made.
These findings were made because our customers answered questions concerning easily identifiable physical traits, such as whether they’re bald, can easily touch their toes and whether their ring finger is longer than their index finger. Comparing this data with their genetics we were able to see connections that could give us greater understanding of links between these seemingly unrelated traits.
Looking at the PAX3 gene again, which contains variants that influence normal facial development, there are variants that are also associated with a syndrome that leads to deafness, facial abnormalities and skin pigmentation irregularities. Variants in another gene HOXD, which is essential for hand and foot development, are also associated with some severe deformities. And variants in the EDAR gene – which influence the baldness, the straightness of your hair and the amount of <a href="https://www.23andme.com/topics/traits/back-hair/">back hair</a> you have – are also associated with ectodermal dysplasias, that effects the development of hair, nails, skin and teeth. So understanding these associations with common but complex traits can also provide insight into rare disorders and conditions.
People fuel 23andMe’s engine of discovery because they choose to answer a few questions about themselves. This has allowed us to answer questions about genetics and it has also allowed us to study over 1,000 different traits and conditions, many of which have never been analyzed in such a large scale. What we’ve gleaned from this data so far is a picture of the complex genetic architecture underlying human differences and point us in the right directions for future study.

The Complex Genetic Architecture Underlying Human Differences

<img loading="lazy" decoding="async" class="alignright size-medium wp-image-1400" title="bloodclot" alt="" src="https://blog-api.23andme.com/wp-content/uploads/2008/09/bloodclot-300x222.jpg" width="300" height="222" />
A <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2812%2960986-6/abstract" target="_blank" rel="noopener noreferrer">study</a> in the journal Lancet regarding a new blood thinning drug brings to mind the difficulty doctors and patients have in using anticoagulants to prevent clots that could otherwise lead to heart attacks or strokes.
The mostly commonly used blood thinner, warfarin (Coumadin ®) has proven to be a godsend for millions of people at risk, but this study suggests that as many as half of those who use the drug do not benefit from it because of challenges related to finding the proper dose.
Calibrating the right prescription of warfarin is notoriously difficult because the right amount depends not just on such things as a person’s size, their diet and age, but also, importantly,their genes.
The new study isn’t about genetics. It’s by<a href="http://www.dukehealth.org/health_library/news/apixaban-superior-to-warfarin-across-wide-range-of-patient-risk-scores"> researchers at Duke Medical Center</a>, who suggest that the new blood thinner apixaban is safer than warfarin and more effective at preventing strokes in people who have atrial fibrillation, a common heart rhythm disorder.
Apixaban hasn’t<a href="https://www.forbes.com/sites/larryhusten/2012/09/27/fda-sets-new-decision-date-for-eliquis-aprixaban/"> yet received FDA approval</a>. That may soon change, but the study reminds us of all the challenges with current drugs and the tremendous amount of resources invested into finding drugs that are safe and effective for more people. Another complementary way to achieve that goal is by learning more about how individual patients may respond to specific drugs. Your genetics are a big part of that equation.
In the case of warfarin, aperson’s genetic<a href="https://www.23andme.com/health/Warfarin-Coumadin-Sensitivity/">s</a> directly impacts how sensitive they are to the drug. Although there are a number of factors that influence a person’s optimal dose of warfarin, genetic variations in the CYP2C9 and the VKORC1 genes play an important role in how the body responds to the drug. More than two years ago the FDA updated the labeling on warfarin to make note of this genetic influence but genetic testing is not required before prescribing warfarin.

Related posts: 
 &#8211;<a href="../2009/02/19/new-study-shows-that-genetic-information-can-improve-administration-of-commonly-used-blood-thinner/"> New Study Shows That Genetic Information Can Improve Administration Of Commonly Used Blood Thinner</a> 
&#8211;<a href="../big-questions/a-prescription-for-personalizing-medicine/"> A Prescription for Personalizing Medicine</a> 
&#8211; <a href="../news/announcements/23andme-launches-first-national-institutes-of-health-funded-study/">23andMe Launches Its First NIH Funded Study</a>

Blood Thinners and the Genetics Behind Drug Response

<img loading="lazy" decoding="async" class="aligncenter size-medium wp-image-3613" title="Grandparent and daughter" alt="" src="https://blog-api.23andme.com/wp-content/uploads/2009/05/istock_000004109962xsmall-300x245.jpg" width="300" height="245" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/05/istock_000004109962xsmall-300x245.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2009/05/istock_000004109962xsmall.jpg 383w" sizes="auto, (max-width: 300px) 100vw, 300px" />
<a href="http://www.23andme.com/topics/health-predispositions/hereditary-hemochromatosis/">Hereditary hemochromatosis</a> is a common genetic condition that makes a person more prone to absorbing too much iron. Premenopausal women are largely protected from iron overload because of menstruation and pregnancy, but typically around menopause some women begin to experience symptoms of the condition.
A <a href="http://annals.org/article.aspx?articleid=710670">study</a> published in the late 1990’s with 176 women and 176 men with hemochromatosis, matched by age, found that a significant number of the women suffered serious complications from hemochromatosis, and developed their first symptoms only a little later than the men. On average, the women in the study showed symptoms around age 50, while the men showed signs nearly two years earlier. Roughly half of the women had stopped menstruating at the time of diagnosis, but the other half were technically premenopausal at diagnosis. There was some evidence that women who stopped menstruating before the age of 50 had higher levels of iron in their bodies.
For certain conditions*, like cirrhosis and diabetes, rates were higher in men, but for others, like fatigue and arthritis, rates were higher in women. Roughly 94 percent of the women, versus 100 percent of men, had abnormal measures of iron stores in the body.
<div style="float: right; text-align: justified; width: 200px; padding: 15px; border: 1px solid #ccc; margin-left: 10px;">Women and Men Have the Same Genetic Risk for Hemochromatosis 
Hereditary hemochromatosis affects women and men equally with respect to how the condition is inherited: you must inherit a mutated gene from each parent to have the condition and the gene involved in most forms of hereditary hemochromatosis, the HFE gene, is not located on the sex chromosomes. (This condition is autosomal recessive.) 
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Thus, the results from this study suggest that women can suffer overt symptoms of hereditary hemochromatosis and at roughly the same age as men. And once a woman goes through menopause and loses her natural way of expelling iron, she appears to have more or less the same risk as a man for suffering serious complications including arthritis and liver disease.
For most women menopause is associated with <a href="http://my.clevelandclinic.org/disorders/menopause/hic_menopause_the_short-term_effects_and_long-term_risks.aspx">various changes in health</a>. In the short term women can attest to unpleasantries that result from drops in estrogen levels. High on the list are hot flashes, changes in sex drive, and mood changes. But there are also serious long term risks for conditions like osteoporosis and heart disease. For women with hereditary hemochromatosis, increased risk for absorbing too much iron should also be added to the list. Women should take note that the symptoms of menopause and hemochromatosis can sometimes overlap, for instance fatigue is common to both.
Whether before or after menopause, it’s important for women with hereditary hemochromatosis to monitor the iron levels in their body. Physicians can order blood tests to measure transferrin saturation and serum ferritin levels in blood, which together provide a good picture of iron absorption and storage in the body. If these markers are elevated, additional testing to determine the impact on organs may also be warranted.
*Liver cirrhosis occurred in ~14 percent of the women and 26 percent of the men; diabetes occurred in ~7 percent of the women and ~16 percent of the men; fatigue occurred in ~65 percent of the women and 42 percent of the men; arthritis occurred in ~45 percent of the women and ~35 percent of the men.

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Hemochromatosis in Women Before and After Menopause

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For a long time prospective fathers could wile away the years without much worry about when to have kids, while prospective moms were constantly checking their ticking biological clocks.
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<div>A<a href="https://www.nature.com/nature/journal/v488/n7412/full/nature11396.html"> recent study</a> may turn the tables a bit. It may push men to think a little more about how long they wait to start a family.The study by DeCODE in Iceland shows that each year a man delays fatherhood he increases the number of new genetic mutations that he passes on to his children.
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<h2>A Calculation</h2>
<div>These “de novo” mutations are not ones that the father was born with. Therefore they are unrelated to any previous family history or condition. They occur spontaneously in the father’s sperm cells.Using the data from the study, 23andMe’s Emily Chang lead the team that  created a simple tool that uses a man’s age to calculate the number of mutations he might pass on to his children.
<img loading="lazy" decoding="async" class="aligncenter wp-image-15995 size-full" title="mutation small" src="http://35.88.189.111/wp-content/uploads/2012/09/mutation-small.jpg" alt="" width="253" height="406" srcset="https://blogcms.23andme.com/wp-content/uploads/2012/09/mutation-small.jpg 253w, https://blogcms.23andme.com/wp-content/uploads/2012/09/mutation-small-187x300.jpg 187w" sizes="auto, (max-width: 253px) 100vw, 253px" />
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<div>So what does the number mean?</div>
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<div>The<a href="https://www.nytimes.com/2012/08/23/health/fathers-age-is-linked-to-risk-of-autism-and-schizophrenia.html"> implication from the study</a> is that the longer a man waits the more he increases the chances his child might develop certain kinds of conditions, such as autism. While the risk may increase, it is still very low.Also, keep in mind that despite the name, mutations are not necessarily bad. In fact, these different spellings within a person’s genetic code are largely benign. Some may even be beneficial and lead to long term genetic diversity among people.
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<h2>A Risk for Autism?</h2>
Science writer Alok Jha pointed out in a<a href="http://www.guardian.co.uk/science/2012/aug/22/older-fathers-genetic-mutations-research"> piece in the Guardian</a> that a single mutation in the APP gene actually protects against Alzheimer’s disease. It also helps people live longer. At the same time, some preliminary studies suggest that the more de novo mutations passed onto a child the higher the risk that child could develop certain types of conditions, such as autism and schizophrenia.
<div>Or as lead author Kari Stefansson, deCODE’s chief executive,<a href="https://www.nature.com/news/fathers-bequeath-more-mutations-as-they-age-1.11247"> told Ewen Callaway at Nature</a>:</div>
<div>
“The older we are as fathers, the more likely we will pass on our mutations. The more mutations we pass on, the more likely that one of them is going to be deleterious.”
For women, who pass on other risks to their children with age, the number of de novo mutations a mom passes on to a child is constant at about 14. The number of new mutations a father passes to a child goes up by two each year. That means that a 50-year-old new father might pass on about 65 new mutations to his child. A father half his age would pass on about 35 mutations. The reason the number of de novo mutations women and men pass on to their children is so different is because women are born with all their eggs. Men on the other hand produce sperm throughout their lifetime, offering more opportunities for mutations to occur.
This doesn’t necessarily mean that men should start having kids or having their sperm frozen right out of college. But it does add more information for prospective fathers to consider. It also gives us a little more understanding about complex conditions like autism.
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Older Dads

<img loading="lazy" decoding="async" class="alignright size-thumbnail wp-image-5677" title="alzheimers" alt="" src="https://blog-api.23andme.com/wp-content/uploads/2009/12/alzheimers-150x150.jpg" width="150" height="150" srcset="https://blogcms.23andme.com/wp-content/uploads/2009/12/alzheimers-150x150.jpg 150w, https://blogcms.23andme.com/wp-content/uploads/2009/12/alzheimers-271x271.jpg 271w" sizes="auto, (max-width: 150px) 100vw, 150px" />
In honor of World Alzheimer’s Day, we’re linking to a few posts and stories about the disease. Alzheimer’s disease is the most common form of dementia and affects more than 35 million people worldwide.
23andMe first began allowing customers to learn about their genetic risk for late-onset Alzheimer’s disease a little more than a year ago. We report on variants of the<a href="https://www.23andme.com/health/alzheimers/"> APOE</a> gene (e2, e3, and e4) and provide a risk estimate for the disease for customers with European ancestry. The 23andMe report also includes detailed background information on Alzheimer’s including other known risk factors for the disease, such as obesity and high cholesterol.
Although some are critical of giving people access to this information, many people say that despite their fear of Alzheimer’s they<a href="https://www.washingtonpost.com/national/health-science/despite-fears-of-alzheimers-many-would-like-to-know-their-risk-for-the-disease/2012/08/10/438eb3ba-6a2c-11e1-acc6-32fefc7ccd67_story.html"> would rather know</a> their risk than remain in the dark about the danger. For some knowing their APOE status and Alzheimer’s risk may encourage them to engage in <a href="http://well.blogs.nytimes.com/2012/01/18/how-exercise-may-keep-alzheimers-at-bay/">activities to stave off</a> the disease, or prompt them to participate in clinical research that could lead to more information about the causes and possible cures for Alzheimer’s.
Recently, scientists discovered a rare genetic variant that may be protective against the disease. In people of Icelandic descent, the T version of the variant (also known as the A673T variant in the APP gene) was associated with about five times lower odds of Alzheimer’s. This finding was <a href="https://www.nature.com/nature/journal/v488/n7409/abs/nature11283.html">first reported in the journal Nature</a> over the summer.
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Health + Traits — Page 27