Scientists have found a fourth gene that is linked to Alzheimer's disease and National Institute on Aging (NIA) neuroscientist Dr. Creighton Phelps believes that this latest gene discovery may yield crucial clues to the molecular underpinnings of this disease. According to Dr. Phelps, "this finding may help scientists unravel the mechanisms that promote Alzheimer's and thus, perhaps, lead eventually to new therapeutic interventions."
In two separate papers which appear in the August 18, 1995, issue of Science, NIA grantees at several institutions announce the discovery of a mutation in a gene on chromosome 1 that is associated with one form of early onset Alzheimer's. This gene abnormality is fairly rare and occurs mainly in descendants of Germans who immigrated to an area near the Volga River in Russia and then to the United States. The early onset form of Alzheimer's caused by the defect on chromosome 1 is less prevalent than late onset Alzheimer's, which occurs in people age 65 and older.
Intriguingly, the chromosome 1 gene bears a striking chemical resemblance (67 percent homology or similarity) to a different gene on chromosome 14 identified as influencing early onset Alzheimer's, but affecting a different set of families. This information gives researchers a significant boost in their understanding of how these genetic abnormalities may influence the development of Alzheimer's because of the similarities in the proteins produced by the genes.