Supercentenarians genes may protect them from disease'Cancel out disease genes'
People who live to be 110 appear to be just as likely to have genes which predispose them to disease as the rest of us, but may have other genes which counteract their effects, scientists say.
Supercentenarians - those who live to be at least 110 - are very rare, with just one in five million people in developed countries reaching this age.
Scientists have long suspected that genes are behind why a fortunate few manage to survive into extreme old age. So, for the first time, US researchers compared and analysed the complete genomes from a man and woman who lived to be more than 114 years old.
The scientists found that the supercentenarians DNA had as many disease-associated genes as the rest of the population.
For example, the 114-year-old man had 37 genetic mutations linked to an increased risk for colon cancer.
Dr Thomas Perls, a study author and director of the New England Centenarian Study, said: "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 woman also had many genetic variations linked to age-related disease, including those for Alzheimer’s, cancer and heart disease. Although she developed congestive heart failure and mild cognitive impairment, these conditions did not become apparent until after the age of 108.
As the two supercentenarians carried as many disease-associated genes as the general population, the scientists said the findings suggested other protective mechanisms could be at work.
Their preliminary findings identified more than 50 variants in genes linked to accelerated ageing, heart disease and Alzheimer's which could have a positive impact on a person's life span as well as their health.
"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," said Dr Perls.
"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, in these individuals who are practically living to the limit of the human lifespan.”
He added: "The study of these two supercentenarians is just the beginning, and genetic study of many more such subjects needs to be performed."
The study findings are published in the journal Frontiers in Genetics.
This article was published on Mon 9 January 2012
Image © fotorf - Fotolia.com
Use this story
Link to this page
Printer friendly version