Protective mutations have so far been found by chance, but researchers are now starting to actively look for them, the New York Times reports.
With the mounds of sequencing data that have recently been collected, researchers like Eric Schadt at Mount Sinai and Sage Bionetworks' Stephen Friend have been looking for people who carry genetic mutations for diseases that appear early in life, but who are healthy.
That's how they stumbled on to Doug Whitney. His mom, nine of her 13 siblings, his older brother, and six cousins have died of early onset Alzheimer's disease. And other family members currently have the condition.
But Whitney, who tells the Times he's been bracing for the onset of the disease for years, has an intact memory at the age of 65. He'd assumed he'd managed to avoid the mutation that runs in his family, but a genetic test he took a few years ago found that he did actually have it.
Another mutation, researchers suspect, might be protecting him. And that's what they are now searching for.
"Instead of trying to fix things that are broken let's look at people where things are broken but nature finds way around it," Schadt tells the Times.