A man whose genetics almost guaranteed that he would develop Alzheimer's disease by his 50s has somehow made it to his mid-70s with nary a symptom.
The now-75-year-old man, Doug Whitney, is one of only three people known to have escaped their genetic fate, sidestepping a rare form of Alzheimer's disease called dominantly inherited Alzheimer's disease (DIAD). Caused by several gene mutations, DIAD makes up less than 1% of all Alzheimer's cases, and its symptoms typically set in between ages 35 and 55.
