The finding should allow physicians to use mutation analysis to better diagnose the neurodegenerative disease in certain families of Caribbean Hispanic heritage and to genetically counsel family members with a familial risk for the disorder, the researchers say.
The investigators, led by Dr. Richard Mayeux, director of the Gertrude H. Sergievsky Center and co-director of the Taub Institute on Alzheimer's Disease, are publishing the results of their study in the Nov. 14 issue of the Journal of the American Medical Association.
"This is the first genetic alteration characterized for early-onset Alzheimer's disease in the Caribbean Hispanic population," Dr. Mayeux says. "The mutation should help us diagnose early-onset Alzheimer's disease in this population group. And Caribbean Hispanics under age 60 who have a history of Alzheimer's disease may consider getting screened for this mutation."
Clinicians recognize two types of Alzheimer's disease: familial, in which multiple family members are affected, and sporadic, when only one member in a family has the disease. They further distinguish early-onset Alzheimer's, which affects people between the ages of 30 and 60, and late-onset disease, which is usually diagnosed in people who are at least 65.
Early-onset disease, which accounts for only 10 percent to 15 percent of the cases, is strongly hereditary. Late-onset is the more common form of the disease, which can be both genetic and sporadic.
In the study, the researchers analyzed the DNA of 44 individuals in 19 families of Caribbean Hispanic descent who had been diagnosed with early-onset Alzheimer's disease. They looked
Contact: Leslie Boen
Columbia University Medical Center