Doug Whitney, 76, carries a rare PSEN2 gene mutation that causes early-onset Alzheimer’s but has shown no cognitive decline despite a family history of the disease. Researchers at Washington University School of Medicine in St. Louis have been studying Whitney to understand why he has resisted the genetic fate. His genetic data and brain scans have been analyzed to uncover the reasons behind his remarkable resistance to the disease. The study published in Nature Medicine found that Whitney’s brain had virtually no buildup of tau, a hallmark protein of Alzheimer’s, despite his genetic predisposition. Researchers believe their findings could lead to targeted therapies to prevent or delay the onset of Alzheimer’s in others.