Single protein could dramatically alter trajectory of Alzheimer's disease

A woman wearing a blue tank top and jeans with long dark hair holds the arm of an older tan man wearing a gray shirt and a baseball cap as they walk down the street, their backs to the camera.

A single gene mutation protects against Alzheimer's disease in people destined to get the disease very young — and now we know why.

The gene mutation affects a protein called reelin that directs brain cells to shred the probable culprits in the disease — toxic amyloid plaques and tau tangles. The mutation makes reelin work much more efficiently, new research reveals.