Familial Aggregation of Alzheimer Disease Among Whites, African Americans, and Caribbean Hispanics in Northern Manhattan

Abstract
ALZHEIMER DISEASE (AD) aggregates in the families of patients with both early- and late-onset disease.1,2 Genetic or environmental factors such as collective exposure to occupational hazards or viral or other infections may explain familial aggregation of AD.3-5 Mutations in 3 genes on chromosomes 1, 14, and 21 result in an autosomal dominant form of AD with early onset.6-8 The ϵ4 isoform of the apolipoprotein E gene on chromosome 19 is also associated with increased risk for AD.9,10 However, the familial distribution of late-onset AD is seldom consistent with a simple mendelian model of inheritance.