A family with an astonishing rate of Alzheimer's disease may harbor a powerful new gene

ELLIJAY, Ga. - Louise Lowman Lee remembers stories about her great-grandmother being put in a fenced area in the backyard, so she could wander safely. She watched her mother patiently care for her grandmother, who lost her reason, inhibitions, and ability to care for herself. Then Alzheimer's disease gradually eroded the brain of her devoted mother,…