In the idyllic American town of Pleasant Hills, Pennsylvania, there lived a family with nine siblings, the youngest a girl named Barb. As the older children headed off to college and started their lives, only Barb was home to see their beautiful, still-young mother fall under a gothic spell, changing into someone she didn't recognize: withdrawn, neglectful, uncaring. Thus begins The Vanishing Family, journalist Robert Kolker's superb follow-up to Hidden Valley Road ("Deeply compassionate and chilling," wrote The Washington Post). This family, we learn, has a genetic mutation that causes dementia, but with an especially cruel twist. As early as their forties, formerly loving parents and hard-driving executives will lose their jobs, have affairs, take up drinking--shed all inhibitions and sense of responsibility--and become people their families hardly know. Their former personalities seem to vanish--and there is a fifty-fifty chance that it will happen to their children, too.

The Vanishing Family unfolds like a heartbreaking thriller as the siblings begin to realize that what happened to their mother is happening to them: first one, then two, three, four, and more begin to change. Sue, in search of a calling, finds her place in caring for the others. Barb sets out to find a cure. Alongside their story, Kolker weaves in the dramatic scientific fight against dementia; after decades of blind alleys, this this family's rare form of FTD (frontotemporal dementia) might lead to a breakthrough in the prevention and treatment of all dementia--including the scourge of Alzheimer's disease. Moving, intimate, unexpectedly hopeful and redemptive, The Vanishing Family is an enthralling narrative about one family's fate, and a medical detective story that speaks to all of us who fear losing ourselves at the end.