Boston University scientists claim to have identified a small
set of genetic variants that accurately predicts extreme
longevity in humans. The scientists, Paola Sebastiani and Thomas
Perls, examined the DNA of 1,055 centenarians living in New
England. They isolated 150 gene variants that were common in
this population. They subsequently examined a separate sample of
centenarians and found that 77% of them had many of the same
genetic variants. The centenarians in the original cohort had as
many disease-associated gene variants as shorter-lived people,
so the scientists reasoned that the genes they had identified
must protect against disease. This conclusion is at odds with
current thinking about extreme longevity which is predicated on
the assumption that long life is caused by the absence of
disease-causing gene variants, rather than the presence of
protective genes. To find the protective genes, the scientists
implemented a genome-wide association study, a technique that
had previously failed to meet expec