Science / Medicine : Alzheimer’s Link Discovered

The discovery of a genetic defect linked to Alzheimer’s disease could someday lead to a treatment, a researcher reported last week. In a presentation at the Jackson Laboratory in Bar Harbor, Me., Allen Roses of Duke University said his study of 32 families with a history of Alzheimer’s revealed a common defect on chromosome 19, one of the 23 pairs of human chromosomes. The progressive neurological disorder afflicts about 4 million Americans.

The finding surprised most researchers studying the disease’s genetics because it had previously been thought to be linked to an abnormality on chromosome 21. That defect is associated with a rare, early-onset form of Alzheimer’s in which memory loss and other symptoms begin to appear around age 40.

Roses speculated that the early-onset form of Alzheimer’s is a different disease. He used his genetic samples to search for a defect on chromosome 21 in late-onset Alzheimer’s disease and could not find it.