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【文摘发布】神秘的，具有普遍意义的肥胖基因
Now, on the genetics front, researchers have nabbed a coveted prize: the first clear-cut evidence for a common gene that helps explain why some people get fat and others stay trim.The British team, led by Andrew Hattersley of Peninsula Medical School in Exeter and Mark McCarthy of Oxford University, doesn’t know what this gene, called FTO, does. But adults, and even children, with two copies of a particular FTO variant weighed on average 3 kilograms more than people lacking the variant, the researchers report in a paper published online by Science this week (www.sciencemag.org/cgi/content/abstract/1141634). Although twin studies have suggested that
obesity has a genetic component, some earlierreports of common obesity genes, including a paper in Science last year (14 April 2006,p. 279), have proved controversial. But this new work, which involved nearly 39,000 people,is solid, says Francis Collins, director of the U.S. National Human Genome Research Institute in Bethesda, Maryland. “There’s no question that this is correct.” The U.K. team first found the gene in type 2diabetes patients participating in a multidisease study sponsored by the WellcomeTrust, the U.K. biomedical charity. Timothy Frayling in Hattersley’s lab and his co-workers
first analyzed the genomes of 1924 diabetic and 2938 nondiabetic individuals, looking for which of nearly 500,000 genetic markers were more common in those with diabetes.Those markers helped them home in on a variant, called a single-nucleotide polymorphism, in the FTO gene. The gene,
located on chromosome 16, was a surprise:Whereas other known diabetes genes predominantly control insulin production,FTO proved to be associated with body mass index, or BMI (weight divided by height squared)—suggesting that it might control weight in more than just people with diabetes.
To find out, 41 collaborators looked for the FTO mutation in DNA samples from “literally every single study we could,” says Hattersley,including another two diabetes populations, nine cohorts of white European adults, and
two studies of European children. In every one, the FTO mutation was associated with BMI. Overall, about 16% of white adults and children carry two copies of this variant. They are 1.67 times more likely than those lacking
any copies to be obese, the group reports. The researchers don’t know what FTO does. But because FTO may lead to a new pathway for controlling weight, “we’ll have people racing to understand” the gene’s function, says obesity researcher Jeffrey Flier of Harvard Medical School in Boston.
Those studies should help unravel the basic biology of obesity.The paper also underscores the importance of tracking down common disease genes in as many groups of people as possible. In the past 2 years, researchers have reported finding common disease genes for age-related macular degeneration, diabetes, and—earlier this month—prostate cancer. However, the finding of another obesity gene, INSIG2, published last year in Science, has
held up in only five of nine populations, says co-author Michael Christman of Boston University. The case for FTO’s involvement is strengthened by the fact that other obesity gene hunters are f inding the FTO polymorphism
as well. “[There’s] very strong evidence that it’s a gene that affects body
weight,” says human geneticist David Altshuler of the Broad Institute in Cambridge,Massachusetts. “That’s very exciting.” 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领 初译：
神秘肥胖基因FTO的发现 初译：
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作者:admin@医学,生命科学 2011-06-16 17:11
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