September 8, 2009

More Alzheimer genetic risk factors found

An international team of scientists led by Cardiff University in Wales has reported finding two more genetic risk factors of Alzheimer's disease.

The group said it completed the largest genome-wide association study ever involving patients with Alzheimer's disease. The study pooled DNA samples from more than 19,000 older European and U.S. residents.

The researchers said previously only four genes had been definitively associated with Alzheimer's disease -- three genetic mutations identified as causes of rare, inherited forms of early-onset Alzheimer's and a fourth gene, APOE4, the only one previously linked to the more common late-onset form of the disease.

In the new study, the scientists identified two new genes that appeared to be involved in elevated risk for Alzheimer's and confirmed the importance of APOE4.

There's good evidence that these new genes may be novel risk factors, the first discovered since APOE in 1993, said Washington University at St. Louis Professor Alison Goate, a co-author of the research. So it's a very important observation because this study is the first to provide such significant evidence of novel genetic risk factors for the most common form of Alzheimer's disease.

The consortium of more than 80 scientists from the United Kingdom, Ireland, German, Belgium, Greece and the United States reports its findings in the online edition of the journal Nature Genetics.