Is the secret to a long life written in your genes? Or will your annual merry-go-rides around the sun be cut short by disease or poor health? The question is intriguing, but difficult to answer. But that hasn't stopped researchers from looking for genes or biological traits that may explain why some people live to be very old while others sicken and die at relatively young ages.
Today, developmental biologist Stuart Kim, PhD, published some very interesting research in PLoS Genetics about regions of the human genome that appear to be associated with extreme longevity (think upper 90s to over 100 years old).
One, a gene called APOE, is associated with the development of Alzheimer's disease. It's been previously been implicated in longevity. However, the other four regions identified by the study are new. They are involved in biological processes such as cellular senescence or aging, autoimmune disease and signaling among cells.
As explained in the journal's press release:
Previous work indicated that centenarians have health and diet habits similar to normal people, suggesting that factors in their genetic make-up could contribute to successful aging. However, prior genetic studies had identified only a single gene (APOE, known to be involved in Alzheimer’s disease) that was different in centenarians versus normal agers.
As we've explained here before, studying the very old is difficult, in part because there are so few of them. That makes it hard to come up with statistically significant results when comparing them to others. For this study, Kim and his colleagues devised a new technique to identify regions of the genome associated with longevity by linking it to the likelihood of developing other common diseases or disease-related traits, including type 2 diabetes, bone density, blood pressure and coronary artery disease.
From the release:
Our study identified APOE and four new loci associated with extreme longevity. The study is an example of using Big Data to glean information about an extremely complicated trait such as longevity. To find the longevity genes, the authors first derived a new statistical method (termed iGWAS) that takes advantage of knowledge from fourteen diseases to narrow the search for genes associated with longevity. Using iGWAS, the scientists found five longevity loci that provide clues about physiological mechanisms for successful aging. These loci are known to be involved in cell senescence, Alzheimer’s disease, autoimmunity and cell signaling.
The incidence of nearly all diseases increases with age, so understanding genetic factors involved in successful aging could have a large impact on health. Future work may lead to a better understanding of how these genes promote successful aging. Also, future studies could identify additional longevity genes by recruiting more centenarians for analysis.
If you're interested in learning more about Kim and the science of aging, you may want to check out a video of a talk he gave in 2014 in Monterey, Calif. for the Stanford+Connects program entitled "How and Why We Age." Or read my magazine article from last year on aging and my favorite lab rat, the killifish.
Previously: "A lot more data" needed to determine what makes supercentenarians live so long, Unlocking the secrets to human longevity and California's oldest person helping geneticists uncover key to aging
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