Working with tissue samples from a cluster of families with histories of early Alzheimer’s, the scientists found that stricken individuals share d a specific mutation on chromosome 1, one of the 23 paired chromosome found in every cell. No one knows just how the newly discovered gene causes trouble, but it closely resembles and Alzheimer’s gene found earlier on chromosome 14. “Finding two similar genes that cause Alzheimer’s is the break we’ve been waiting for,” says Dr. Gerard Schellenberg, who led the Seattle team. Though the genes relate most closely to early-onset Alzheimer’s, they should help illuminate all types of the disease–and speed the search for treatments.
