Friday, November 14, 2014

Researchers have just sequenced the genomes of 17 “supercentarians” -- people over 110 years of age -- and conclude that these long-lived individuals likely have genes that promote longevity, but the fountain of youth component remains elusive so far. The good news, or bad, depending on how you look at it, is that lifestyle choices don’t seem to matter much for those hoping to reach such advanced ages, according to the study, which is published in the latest issue of PLOS ONE. The Oldest Living Things in the World: Photos “Lifestyle choices in terms of smoking, alcohol consumption, exercise, or diet do not appear to differ between centenarians and controls,” wrote Hinco Gierman and colleagues. “Controls” in this case refers to younger people who served as comparisons. That aspect isn’t too surprising, given all of the interviews with people aged 100+ who say they still enjoy a glass of wine, a cigar or other indulgence, although most indicate that they do such things in moderation. Gierman, of the Stanford University Departments of Developmental Biology and Genetics, and his team limited the majority of their analysis to 13 genomes from Caucasian females, just to avoid other major differences that might exist between various genomes. The researchers suspect that super old people may be “enriched for a rare protein-altering variant” or variants that confer extreme longevity. A possibility for the fountain-of-youth source is a gene called TSHZ3. “From our gene-based analysis, the gene showing the most enrichment for protein-altering variants in supercentenarians compared to controls was the TSHZ3 transcription-factor gene,” the researchers wrote. “Because it was the top hit,” they added, “we pursued this gene further in a study consisting of 99 genomes from subjects aged 98–105 years old. We found that TSHZ3 carried protein-altering variants in more of the long-lived subjects than the controls.” The effect wasn’t incredibly strong, though. Instead, the researchers now suspect that multiple genes somehow come into play. An interesting finding is that one of the supercentarians had a disease-associated genetic variant associated with a terrible heart condition. Some people with this pathogenic allele keel over from sudden cardiac death. Clearly that didn’t happen to this woman, who reached a ripe old age. Oldest Human Ancestor Found in Lake Sludge Cancer risk also seems to be lessened for supercentarians. The researchers report that there is a 19 percent lifetime incidence of cancer in the world’s oldest people compared to 49 percent in normal population. The scientists have made their new data available on Google Genomics, so anyone researching longevity can have a go at finding the key, or keys, to a long life. They concluded, “Supercentarians are extremely rare and their genomes could hold secrets for the genetic basis of extreme longevity.” Photo: A 95-year-old Chilean man smiling. Credit: Diego Grez, Flickr http://news.discovery.com/human/genetics/worlds-oldest-people-are-genetically-superior-141112.htm#mkcpgn=rssnws1

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