A genetic mutation that makes cells less responsive to growth hormone has been linked to human longevity, Scientific American reports. A recent study looked at children of Ashkenazi Jews with a family history of long life and an average age of 98, and compared their genes with the children of other Ashkenazi who died around age 68. The mutation suppressing response to the growth factor IGF1 showed up in the former group.
The mutation has previously been linked to longevity in animals; suppressing IGF1 has been shown to double the lifespan of mice. Scientists note that blood levels of the hormone were 35% higher in the centenarians who had mutations than in the control group, suggesting that the body tries to compensate for the lack of responsiveness.