Link between longevity, genes studied

People who live 110 years or longer have as many disease-associated genes as those in the general population, but they may also be blessed with protective genes that help them live so long, researchers report.

In what they describe as a first-of-a-kind study, the team of U.S. scientists analyzed the whole genome sequences of a man and a woman who lived past the age of 114 and found that they had as many disease-associated genes as other people.

The man had 37 genetic mutations associated with increased risk for colon cancer.

"In fact, he had presented with an obstructing colon cancer earlier in his life that had not metastasized and was cured with surgery. He was in phenomenal cognitive and physical shape near the time of his death," the study's senior author, Dr. Thomas Perls, director of the New England Centenarian Study, said in a Boston University Medical Center news release.

The woman had many genetic variations associated with age-related disease, such as heart disease, cancer and Alzheimer's. She developed congestive heart failure and mild cognitive impairment, but these conditions didn't become evident until she was more than 108 years old.

"The presence of these disease-associated variants is consistent with our and other researchers' findings that centenarians carry as many disease-associated genes as the general population," Perls said. "The difference may be that the centenarians likely have longevity-associated variants that cancel out the disease genes. That effect may extend to the point that the diseases don't occur -- or, if they do, are much less pathogenic or markedly delayed towards the end of life."

The study was published Jan. 3 in the journal Frontiers in Genetics.