March 10, 2008 -- Having two parents with Alzheimer's disease could make Alzheimer's more likely.
That's according to a new study of 111 families in which both parents had Alzheimer's disease.
Of the nearly 300 children in those families, 22.6% developed Alzheimer's disease.
For comparison, 6% to 13% of the general public develop Alzheimer's after age 65, according to government statistics cited by the researchers, who included Suman Jayadev, MD, of the University of Washington's neurology department.
Jayadev's team cautions that the findings may be an underestimate because many of the adult children in the study were younger than 65. Alzheimer's disease becomes more common with age, but it isn't a normal part of aging.
A family history of Alzheimer's disease beyond parents didn't affect the odds of developing Alzheimer's disease, the study shows.
People who inherited the ApoE4 gene variation, which is linked to Alzheimer's, were particularly likely to develop Alzheimer's disease. But ApoE4 didn't fully explain the results, so the researchers reason that other genes must be involved in handing down Alzheimer's risk.
The study appears in the March edition of the Archives of Neurology.