<img loading="lazy" decoding="async" class="alignright size-full wp-image-1219" title="figureonpier" src="https://blog-api.23andme.com/wp-content/uploads/2008/09/figureonpier.jpg" alt="" width="350" height="232" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/09/figureonpier.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2008/09/figureonpier-300x199.jpg 300w" sizes="auto, (max-width: 350px) 100vw, 350px" />
Biomedical research conducted in the last decade has impressed upon society that mental illnesses such as <a href="https://blog.23andme.com/2008/03/28/schizophrenia-genetics-in-science-snps-are-only-one-piece-of-the-puzzle/">schizophrenia</a>, <a href="https://www.ncbi.nlm.nih.gov/pubmed/18669994?ordinalpos=6&amp;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum">alcohol dependence</a> and <a href="https://www.ncbi.nlm.nih.gov/pubmed/17938638?ordinalpos=39&amp;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum">major depression</a> can have genetic bases. Unfortunately, the public’s scientific knowledge has not necessarily translated into social acceptance.
“The landscape surrounding mental illness has changed a great deal over the last decade. Support for medical treatment has grown, but tolerance for the mentally ill … remains low.”
<h2>Nationwide Survey</h2>
University of Pennsylvania sociologist Jason Schnittker came to that conclusion after comparing the results of nationwide surveys given in 1996 and 2006, looking at the data provided by 1,400 respondents in each case on the public perception of mentally ill people.
His work was published online earlier this month in the journal Social Science and Medicine.
The General Social Survey tracks social and demographic trends and is conducted every other year. Schnittker chose to study the results of the mental health sections of the survey only.
The respondents were presented with three short stories, each involving a person described as having schizophrenia, alcohol dependence or major depression – though the survey did not identify them as such. After reading about the characters, the respondents were asked how likely they thought each person’s mental illness was to be caused by reasons ranging from environmental factors such as stress, to a genetic problem, to God’s will.
<h2>Genetic Factors</h2>
The results suggest that genetic associations for these conditions lead to increased support for medical treatments, but have little positive effect on respondents’ tolerance for the mentally ill.
For example, Schnittker found respondents strongly supported medical treatment for the character with schizophrenia, even to the point of legally requiring it, in part because their increased understanding of the illness as genetically based was correlated with their perception of schizophrenics as dangerous. On the other hand, survey respondents did react react somewhat more favorably toward the character with depression in 2006 compared to 1996, and were more socially accepting.
“In this case,” Schnittker wrote, “depression is no longer seen as a sign of personal weakness, but rather is seen as a disease to be nurtured, treated and perhaps accepted as natural.”

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23andMe Blog Team

Study Finds Genetic Information Has Done Little to Increase Tolerance of Mental Illness

<img loading="lazy" decoding="async" class="alignright size-full wp-image-1182" title="cll" src="https://blog-api.23andme.com/wp-content/uploads/2008/08/cll.jpg" alt="" width="300" height="226" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/08/cll.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2008/08/cll-300x226.jpg 300w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Researchers have added chronic lymphocytic leukemia (CLL), the most common type of leukemia in western countries, to the long list of diseases that have been associated with common genetic variants.
<a href="http://www.cancer.gov/cancertopics/pdq/treatment/CLL/patient/" target="_blank" rel="noopener noreferrer">CLL</a> is caused by abnormal, uncontrolled growth of immune cells called B-cells. Usually, there are no obvious symptoms and the disease is detected only during a routine blood test. In the United States, about 15,000 new cases of the disease are diagnosed each year.
Because there is a familial basis to the disease, a role for genetics in CLL has long been suspected. First-degree relatives of patients have a seven-fold increased risk for the disease. But so far, no clear contenders for the “CLL gene” have been found. This suggested to researchers that instead of there being one or two genes with large effects to be found, there might instead be multiple genetic risk factors for CLL, each contributing a small amount to the risk.
By studying about 1,500 British people with CLL and about 3,000 controls, <a href="https://dx.doi.org/10.1038/ng.219" target="_blank" rel="noopener noreferrer">Di Bernardo et al</a> found six distinct SNPs associated with CLL. These results, published online today in Nature Genetics, not only begin to shed light on the genetics of the disease, but they also give researchers clues about its biological basis.

For about 54 percent of people of European ancestry who have three or fewer &#8220;risky&#8221; copies out of a possible 12 (two copies each for six SNPs), there is no significant difference in the risk of developing CLL. Having six risky copies ups a person&#8217;s odds about 3.8 times over those with none, and the 2.1 percent of that population who are unlucky enough to have seven risky copies have approximately eight-fold increased odds of developing CLL.
Although it’s far from certain that these six SNPs are actually causative factors for CLL, the authors note in their report that it will be intriguing to see if the SNPs are associated with CLL in non-Europeans. Both Asian and African populations have lower frequencies of the risky versions of each of the six SNPs &#8212; and lower rates of CLL.
Image: Mary Ann Thompson/GNU Free Documentation License

Researchers Find First SNPs Linked To Common Type of Leukemia

<img loading="lazy" decoding="async" class="alignright size-full wp-image-1138" title="fundus" src="https://blog-api.23andme.com/wp-content/uploads/2008/08/fundus.jpg" alt="" width="295" height="219" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/08/fundus.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2008/08/fundus-300x223.jpg 300w" sizes="auto, (max-width: 295px) 100vw, 295px" />
A new treatment for one type of age-related macular degeneration that is currently in clinical trials may have an unintended consequence: it could cause another form of the disease.
Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss in the western world among people over 60. The two forms of the disease — wet and dry —both cause vision loss by destroying cells in the central portion of the retina.
In the last few years, progress in understanding AMD has been made thanks in part to the discovery of several genetic variants linked to both forms of the disease. Yesterday a report published online in the <a href="http://content.nejm.org/cgi/content/full/NEJMoa0802437" target="_blank" rel="noopener noreferrer">New England Journal of Medicine</a> described yet another AMD genetic association, this time specific for the dry form of the disease.
The variant is in the gene for toll-like receptor 3 (TLR3), a protein that helps the immune system fight off viruses.
“What TLR3 does in the case of infection is sacrifice an infected cell to protect the neighborhood,” said the study’s senior author Kang Zhang in a statement.

Lab tests in human eye cells and genetically engineered mice found that the T version of the SNP decreases TLR3’s cell killing potential by reducing its activation in response to viral cues. Studies of patients and controls found that version of the SNP also decreases the risk of developing dry AMD.
“This discovery has significant implications for diagnosing the dry form of AMD, which is the most prevalent form. It also allows us to develop new drugs to the treat the dry form of AMD, for which there is currently no treatment,” Zhang said.
Jayakrishna Ambati, another author of the study, plans to start clinical trials testing the effectiveness of TLR3 inhibitors in patients at risk for developing dry AMD next year.
The discovery of the role of TLR3 activation in dry AMD may have come just in time. Several drugs for the treatment of wet AMD currently in clinical trials may actually trigger the protein, thus treating one form of the disease while causing the other.
The new treatments for wet AMD are based on a general method called RNA interference (RNAi) that uses short RNA molecules to interrupt genes. In wet AMD, the goal is to disrupt genes involved in the aberrant blood vessel growth seen in the eyes of patients.
Research from <a href="https://www.ncbi.nlm.nih.gov/pubmed/18368052?ordinalpos=1&#038;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum" target="_blank" rel="noopener noreferrer">Ambati’s lab </a>published earlier this year, however, found that RNAi treatments (regardless of their target), activate TLR3. The immune protein confuses the RNA molecules with the genetic material of viruses, its sworn enemies.
People with the another variant that is protective against AMD might still be good candidates for RNAi treatments for wet AMD. Their TLR3 proteins are naturally less reactive. But for the 43% of people of European ancestry with two copies of the more deliterious variant, these treatments could do more harm than good.
“Ironically, in some individuals, using RNAi to cure wet AMD might actually increase the risk for blindness from dry AMD,” Zhang said.

Genetic Link to Dry-type Macular Degeneration Could Spell Trouble For Experimental Wet-type Treatment

<img loading="lazy" decoding="async" class="alignright size-full wp-image-1070" title="aglet" src="https://blog-api.23andme.com/wp-content/uploads/2008/08/aglet.jpg" alt="" width="350" height="233" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/08/aglet.jpg 350w, https://blogcms.23andme.com/wp-content/uploads/2008/08/aglet-300x200.jpg 300w" sizes="auto, (max-width: 350px) 100vw, 350px" />MrPumpernickel / www.instructables.com
The daily rigors of tying and untying would soon render our shoelaces frayed and useless if it weren’t for those protective plastic aglets on the ends. Roughly the same situation exists for the chromosomes in your cells. Without protective pieces of DNA on their ends called “<a href="https://www.nature.com/jid/journal/v118/n5/fig_tab/5601470f3.html?url=/jid/journal/v118/n5/full/5601470a.html#figure-title" target="_blank" rel="noopener noreferrer">telomeres</a>”, repeated rounds of DNA copying would lead to chromosomal breakdown.
The cellular machinery that replicates DNA before cells divide isn’t able to make it to the very end of chromosomes. If it weren’t for the disposable buffer created by the thousands of repetitive DNA base pairs that make up telomeres, critical bits of genetic information would be lost with every cell division.

This protection only can last only so long, however. After 50 or so generations, a cell’s telomeres get so short that they can no longer maintain the genome’s integrity, signaling the end of the line for the cell.
Studies have shown that the “normal” telomere length varies from person to person, but is <a href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1918314" target="_blank" rel="noopener noreferrer">genetically influenced </a>. In the August 15 issue of Human Molecular Genetics, Massimo Mangino and his colleagues from the University of Leicester identify a gene variant that could play a role in determining telomere length among people with European ancestry.
The researchers <a href="http://hmg.oxfordjournals.org/cgi/content/abstract/17/16/2518" target="_blank" rel="noopener noreferrer">found</a> that people with the C version of rs2630578 have telomeres in their white blood cells that are between 400 and 800 base pairs shorter than people with two copies of the other version of this SNP. The authors estimate that this is the equivalent of having cells that are comparatively about 15 to 20 years older, though no actual effects on aging or health were associated with this SNP in the study.
The variant lies in the BICD1 gene, which is part of a cellular pathway regulating protein movements throughout the cell. Studies in yeast have found associations between transport genes like BICD1 and shorter telomeres, but this is the first time such a link has been seen in human studies.
Mangino and his colleagues found that the C version of rs2630578 decreased the amount of BICD1 protein made by cells, which they theorize might affect telomere length. Having either one or two Cs at this SNP seemed to have about the same effect on BICD1 levels, indicating that having two copies of this SNP version might not be any worse than having only one.
As the first study to associate a SNP with telomere length, further work is needed to confirm these findings – and to see if the same SNP might be involved in conditions where shorter telomeres are known to be a factor, such as <a href="https://www.ncbi.nlm.nih.gov/pubmed/18054991?ordinalpos=4&amp;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum" target="_blank" rel="noopener noreferrer">premature aging syndromes</a> and <a href="https://www.ncbi.nlm.nih.gov/pubmed/18656239?ordinalpos=4&amp;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum" target="_blank" rel="noopener noreferrer">cancer</a>.

A Genetic Variation Associated with Telomere Length

Just about every week a new genome-wide association study links common variations in the genome to some disease. But only rarely do the authors of these studies have more than a guess of why these SNPs are associated with a particular condition.
On Sunday in the online edition of <a href="https://www.nature.com/ng/journal/vaop/ncurrent/abs/ng.215.html" target="_blank" rel="noopener noreferrer">Nature Genetics</a>, researchers presented results that may bring them closer (though not all the way) to understanding one SNP recently associated with Crohn’s disease.
Each copy of a C at rs13361189 increases a person’s risk of developing Crohn’s disease 1.33 times compared to someone with two copies of a T. This SNP lies very close to IRGM, a gene for a protein involved in clearing out bacteria that invade cells. A SNP in another gene involved in this same process, known as autophagy, has also been linked to Crohn’s disease.
It makes sense that genes involved in autophagy would influence a person’s risk for Crohn’s, because the body’s ability deal with bacteria in the intestines is thought to be at the heart of this inflammatory bowel disease. Yet studies have failed to find anything in the IRGM gene itself that could account for this particular SNP’s association with Crohn’s.
McCarroll et al show in their current study that people with the C version of rs13361189 also have a large deletion of about 20,000 DNA bases in front of the IRGM gene that people with the T version don’t have.

The deletion appears to regulate how much protein is made from the IRGM protein, although exactly how it does this is not clear. In laboratory tests the deletion caused some cell types to make more protein, while others made less.
The researchers can’t say which direction the deletion is working in the intestines, but they do know that the amount of IRGM protein affects cells’ autophagy abilities. Lab tests also showed that cells with more IRGM are better able to engulf and destroy invasive bacteria compared to cells with less.
More research will be needed to fully understand the meaning of variations in the IRGM gene, as well as the <a href="https://blog.23andme.com/2008/06/30/snpwatch-number-of-snps-associated-with-crohn%e2%80%99s-disease-triples/" target="_blank" rel="noopener noreferrer">more than thirty other SNPs</a> so far associated with Crohn’s. As scientists begin to understand the functional consequences of the variations, they will gain valuable insight into the mechanisms of the disease that may some day lead them to new and better treatments.

Researchers Find Biological Basis For Crohn’s Association

<img loading="lazy" decoding="async" src="https://blog-api.23andme.com/wp-content/uploads/2008/08/dyson.png" alt="" title="dyson" class="alignright size-full wp-image-1047" width="130" height="170" />
As science types, we&#8217;re often mystified – and maybe just a little exasperated – by the details of health care policy. But 23andMe director Esther Dyson has a very interesting <a href="http://healthaffairs.org/blog/2008/08/21/health-it-intelligent-evolution/#more-425">post</a> on the blog of the policy journal Health Affairs that we recommend.
It&#8217;s very interesting to hear what Esther, a person who often seems to be thinking a few steps ahead of the rest of us, has to say about what will happen as consumers take a more active role in their own health care:
<blockquote>
Years ago, Intuit’s Quicken let people manage a checkbook online and print out checks. As the world moved online, Intuit built interfaces to the online banking services of certain major banks so that users could upload and download their financial information. Pretty soon after that, the less-popular banks built their own interfaces to Quicken in order to capture or regain market share. None of them really wanted to let users mingle data from one source with data from another . . . but of course it happened. And now, users can use Mint or Wesabe [a company that Esther invests in] not just to mingle data but to analyze it, to compare their own spending patterns with others’ and (here’s the business model) to receive “offers” from other financial institutions based on those spending patterns.
I expect exactly the same thing to happen with health information. And, just as banks compete (mostly with success) to keep customers’ money and data safe, so will the organizations that handle users’ medical information. This doesn’t actually require any legislation or standards to happen. Companies are already emerging that will provide interfaces to the IT systems of market-leading health care and insurance providers; eventually, the laggards will adapt to the market standards set by the leaders.
</blockquote>
Once those standards are in place, Esther predicts that our health care system will benefit greatly from the availability of all that data. For one thing, the availability of data will enable research that leads to better treatment. But perhaps most provocative is the prospect that health providers could be rewarded not just for going through the motions, but actually improving their patients&#8217; lives.

Patients are Consumers: Esther Dyson on the Evolution of Health Care IT

<img loading="lazy" decoding="async" class="alignright size-full wp-image-1035" title="Peacock" src="https://blog-api.23andme.com/wp-content/uploads/2008/08/istock_000000236820xsmall-300x225.jpg" alt="" width="300" height="225" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/08/istock_000000236820xsmall-300x225.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2008/08/istock_000000236820xsmall.jpg 400w" sizes="auto, (max-width: 300px) 100vw, 300px" />
An animal&#8217;s ability to survive often depends on how well it can avoid predators.   Many species of fish, birds, and mammals have evolved ingenious methods of staying hidden from predators by blending into the background in one form or another.   But what about animals that do the opposite?   How and why would such attention-grabbing features as a lion’s mane, a male deer’s antlers, or a peacock’s tail evolve?   As it turns out, these traits can be explained by something called sexual selection.   Sexual selection is an aspect of evolutionary theory developed by Charles Darwin in the 19th century after he began to notice many traits that were exaggerated, especially among the male members of the species.   Darwin reasoned that within a species, there must be a &#8220;struggle between the individuals of one sex, generally the males, for the possession of the other sex.&#8221;   So in the same way that women may prefer men with broad shoulders, female peacocks prefer their male counterparts to have ornate feathers — the larger the better. Evolutionary biologists have understood the concept of sexual selection for years, but there has been much debate over how this process occurs at the genetic level.   For example, male and female lions have basically the same set of genes. So how are these genes modified such that male lions develop a mane while females do not?   The answer, as it turns out, is surprisingly simple.
 In this week’s issue of Cell, molecular biologists tackled the question of how sexual selection works by examining the genetics of fruit flies. Male fruit flies have evolved a unique coloring pattern on their abdomens that apparently attracts females in the same way that a peacock’s feathers do.   Females lack the markings, yet they have basically the same genome males do. So how is it that the same basic genome (aside from sex chromosomes) can lead males and females to develop different physical traits? According to University of Wisonsin-Madison biologist Sean Carroll, &#8220;The flies did not need new genes … they just changed how males and females use a common set of genes.&#8221; Carroll and his team discovered that while both male and female fruit flies have the genes necessary to create the abdominal coloring pattern, it is only the males who have that gene switched on.   In female fruit flies, this gene lies dormant. “With this particular trait, it evolved by exploiting (genetic) information that was already there to make male bodies different from female bodies,’ explains Carroll. So how does the genetics of a coloring pattern on fruit fly abdomens apply to sexual selection in other species?   According to Carroll and his colleagues, the same genetic mechanisms that are at play in the fruit fly also operate in a multitude of other animals — including lions, deer, peacocks, and even humans.   This study, in showing the genetic means for how sexual selection may operate, illustrates the ingenuity of evolution — how a seemingly simple genetic switch can create such beautiful and elaborate features in the male members of thousands of the world’s species.

Is That a Peacock Feather under your Coat … Or are You Just Happy to See Me?

<img loading="lazy" decoding="async" class="alignnone size-medium wp-image-1011" title="cigarettes2" src="https://blog-api.23andme.com/wp-content/uploads/2008/08/cigarettes2-300x225.jpg" alt="" width="300" height="225" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/08/cigarettes2-300x225.jpg 300w, https://blogcms.23andme.com/wp-content/uploads/2008/08/cigarettes2.jpg 640w" sizes="auto, (max-width: 300px) 100vw, 300px" />
Tobacco use is the leading cause of preventable deaths in the United States – every year it kills nearly 440,000 Americans.
While about 70 percent of the 45 million Americans who currently smoke have said they want to quit, the Centers for Disease Control and Prevention estimates that only about 10 percent of them will succeed, due in large part to the addictive qualities of the active ingredient in tobacco, nicotine.
Researchers have been looking at the genetic basis of nicotine dependence, characterized by tolerance to the drug and the presence of withdrawal symptoms in its absence, with the long-term goals of better assessing a person’s risk for addiction and potentially developing targeted treatments.
Last year, Laura Bierut and her colleagues at the Washington University School of Medicine <a href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&amp;pubmedid=17135278" target="_blank" rel="noopener noreferrer">identified</a> a single variant in a nicotine receptor that increases a person’s risk of developing nicotine dependence. A later study indicated the same SNP can actually reduce the risk of developing cocaine dependence. And now a study published this month by Bierut and her colleagues shows that the variant also influences how much pleasure a first-time smoker will experience from the first puff of a cigarette.

&#8220;The type of variant you have at this particular receptor – the alpha-5 nicotinic receptor – may actually predict whether or not you will do well on nicotine replacement therapy,&#8221; Bierut said in a statement at the time.
The version of SNP that can increase the risk for nicotine addiction is found at <a href="https://www.ncbi.nlm.nih.gov/pubmed/18519524?ordinalpos=1&amp;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum" target="_blank" rel="noopener noreferrer">appreciable levels</a> only in European populations. People with two copies of the less common A version of the SNP are twice as likely to develop nicotine dependence when exposed to smoking than people with two copies of the more common G version.
A new study from Bierut’s group published this month in the journal Addiction shows that the same version of previously associated with nicotine dependence is also linked to the pleasurable rush some first-time smokers get. Each A at increased a person’s odds of having found that first puff pleasurable by 1.6 times compared to people with no copies of an A. This “buzz” was in turn associated with an 8-fold increase in odds of being a current smoker.
&#8220;The finding of a genetic association with pleasurable early smoking experiences may help explain how people get addicted – and, of course, once addicted, many will keep smoking for the rest of their lives,&#8221; said the study’s senior author Ovide Pomerleau in a statement.
&#8220;It appears that for people who have a certain genetic makeup, the initial physical reaction to smoking can play a significant role in determining what happens next. If cigarette smoking is sustained, nicotine addiction can occur in a few days to a few months.&#8221;
Bierut’s research on SNP also extends to addictive substances other than nicotine. Back in June, her group released a study that examined cocaine addicts and non-drug abusing controls to <a href="https://www.ncbi.nlm.nih.gov/pubmed/18519132?ordinalpos=1&amp;itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum" target="_blank" rel="noopener noreferrer">show</a> that having the nicotine dependence-predisposing A version of this SNP actually decreases the risk for cocaine dependence. Having one A decreases the odds of cocaine dependence risk by about 33 percent; two copies decrease the odds by about 45 percent.
The involvement of this SNP in both nicotine and cocaine addiction, and its opposing effects, may seem perplexing. But Bierut and her colleagues suggest that the answer lies in how each addictive substance affects dopamine in the brain’s reward pathway — a key player in the pleasurable feelings produced by drugs that can lead to addiction.
Nicotine triggers the release of dopamine, a neurotransmitter that activates pleasure pathways in the brain. In contrast, cocaine produces pleasurable feelings by <a href="http://thebrain.mcgill.ca/flash/i/i_03/i_03_m/i_03_m_par/i_03_m_par_cocaine.html#drogues" target="_blank" rel="noopener noreferrer">preventing</a> the dopamine that is naturally released in the brain from being reabsorbed when its job is done. Excess dopamine hangs around in the brain and produces the “high” associated with the drug.
The nicotine receptor that affects is involved in normal dopamine release, even in the absence of nicotine. So when the A version of this SNP dials down the receptor’s activity, natural dopamine release is reduced. This means there is less dopamine available for cocaine to keep around in the brain, and the amount of pleasure the drug can induce is diminished, possibly enough to keep a person from getting addicted.
Image from <a href="http://www.freedigitalphotos.net/details.php?gid=137&amp;sgid=&amp;pid=1389" target="_blank" rel="noopener noreferrer">FreeDigitalPhotos.net</a>

Gene Variant that May Counter Cigarette Cravings

In a recent post we used an analysis of Craig Venter’s genome to illustrate how much has yet to be learned about the relationship between genetic variation and health-related traits.
<img loading="lazy" decoding="async" class="alignright wp-image-916 size-medium" title="craigventer1" src="http://35.88.189.111/wp-content/uploads/2008/08/craigventer1-207x300.png" alt="" width="207" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/08/craigventer1-207x300.png 207w, https://blogcms.23andme.com/wp-content/uploads/2008/08/craigventer1.png 241w" sizes="auto, (max-width: 207px) 100vw, 207px" />
A new paper by Venter and colleagues at his Rockville, Maryland-based institute provides a prime example. Writing in the September issue of Clinical Phamacology &amp; Therapeutics, Venter et al. argue that knowing how genetic differences between ethnicities affect patients’ reactions to certain medications isn’t good enough. To make sure patients get the best healthcare, they say, doctors should be looking at how each person is likely to respond to a particular drug regimen based on his or her unique genetic makeup.
“Even the term ‘Caucasian’ can be deceptive,” the authors noted. “If a self-identified Caucasian originates from a founder population in which certain disease-specific alleles occur at higher frequencies (e.g. Quebec French Canadians or Ashkenazi Jews), his or her doctor may miss an important aspect of the patient’s medical history. One’s ethnicity/race is, at best, a probabilistic guess at one’s true genetic makeup.” 

<img loading="lazy" decoding="async" class="alignnone size-medium wp-image-1005" title="james watson" src="https://blog-api.23andme.com/wp-content/uploads/2008/08/watson1-240x300.jpg" alt="" width="240" height="300" srcset="https://blogcms.23andme.com/wp-content/uploads/2008/08/watson1-240x300.jpg 240w, https://blogcms.23andme.com/wp-content/uploads/2008/08/watson1-768x958.jpg 768w, https://blogcms.23andme.com/wp-content/uploads/2008/08/watson1-821x1024.jpg 821w, https://blogcms.23andme.com/wp-content/uploads/2008/08/watson1-705x880.jpg 705w, https://blogcms.23andme.com/wp-content/uploads/2008/08/watson1.jpg 885w" sizes="auto, (max-width: 240px) 100vw, 240px" />
To further emphasize the differences between people within the same ethnic group, the authors compare the publicly available genome sequences of Venter himself and Nobel Prize winner James Watson, focusing on six genes involved in drug metabolism.
One of those genes revealed a substantial difference between the two men. CYP2D6 is involved in the metabolism of various drugs for high blood pressure, heart arrhythmia and depression. Venter’s genotype indicates that like most Europeans he is an “extensive metabolizer” of such drugs; but Watson’s genotype puts him in the “intermediate metabolizer” category, which is more common among Asians.
Using race as a guide, the authors noted, a physician would have no reason to expect Venter and Watson to react differently to drugs that are metabolized by CYP2D6.
Venter and his colleagues conclude by emphasizing the need for personalized health care based on genomic information, adding that the cost to do so is dropping rapidly.
“Given the complex nature of drug responses, it would ultimately better serve all to dissect the relevant factors of a drug response instead of categorically stereotyping a culture with a presumed genetic background.”
Images: Venter photo by Michael Janich; Watson photo courtesy of the National Library of Medicine

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