Family History May Add to Alzheimer's Puzzle (HealthDay)

TUESDAY, July 29 (HealthDay News) -- The gene most oftenassociated with Alzheimer's disease doesn't provide a complete picture ofoverall risk, according to researchers who analyzed family histories ofthe disease.

Previous research has shown that people with the E4 variant of the APOEgene have a greater risk of developing Alzheimer's, but this new DukeUniversity Medical Center-led study is one of only a few to examine therole of both APOE and family history together.

"We've learned that APOE genotype does not tell the whole geneticstory. Other genes may be acting independently of APOE to influencesomeone's risk for developing the disease," lead investigator Kathleen A.Welsh-Bohmer, director of Duke's Bryan Alzheimer's Disease ResearchCenter, said in a Duke news release.

The study included more than 5,000 people in Cache County, Utah, whowere 65 and older when they were enrolled in the study in 1995. About3,000 of the participants who provided DNA and details about their familyhistory of Alzheimer's were grouped according to the family history of thedisease and whether they had the APOE E4 variant.

"Over an average of seven and a half years of observation, the peoplewho experienced the most significant cognitive decline had a familyhistory of the disease and one or more copies of APOE E4," Kathleen M.Hayden, an assistant professor of geriatric psychiatry, said in the Dukenews release.

"For this reason, researchers should focus not only on people at riskbecause of the APOE gene, but also those who have a family history ofAlzheimer's disease. Conversely, studying those who survive to late oldage without disease is important to discover genes that may offerprotection against the disease."

The study was expected to be presented Tuesday at the Alzheimer'sAssociation's International Conference on Alzheimer's Disease, inChicago.

"These data provide further evidence that we must explore other geneticavenues to learn more about who is at risk for cognitive decline anddementia," Welsh-Bohmer said.

More information

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