January 18, 2006

Scientists Close in on Alzheimer’s Genes

A locus on chromosome 10 appears to be a hot spot, researchers say

The genetic underpinnings of Alzheimer's may just have gotten a little clearer.

An international research team led by investigators at Washington University School of Medicine in St. Louis say they've identified a region of DNA lying on chromosome 10 that's strongly associated with Alzheimer's disease.

The finding narrows the search for a gene in that area that causes Alzheimer's. The study appears in the January issue of the American Journal of Human Genetics.

"There are a few genes that have been implicated in the development of early-onset Alzheimer's disease, but other than APOE, no genes have been found that increase risk for the more common, late-onset form of the disease," principal investigator Alison M. Goate, a professor of genetics in psychiatry at Washington University, said in a prepared statement.

"The region of DNA identified in our study showed evidence of replication in four independent series of experiments. I haven't seen a putative risk factor show such consistent results since the e4 variant of the APOE gene was identified as a risk factor for late-onset Alzheimer's disease more than 10 years ago," Goate said.

The region of chromosome 10 pinpointed by Goate and her team contains six genes.

"We don't know which of those genes is most likely to harbor this particular risk factor for Alzheimer's disease, but we're getting closer. We're now trying to nail down which one of these six genes is the most likely to be involved," Goate said.

She expects that a total of five to 10 genes eventually will be identified as possible risk factors for late-onset Alzheimer's. It's possible that chromosome 10 contains more than one of those genes.

More information

The U.S. National Institute on Aging has more about Alzheimer's disease.