Alzheimer Disease 16

For a general phenotypic description and a discussion of genetic heterogeneity of Alzheimer disease (AD), see 104300.

Mapping

In a genomewide association study of 844 patients with late-onset Alzheimer disease and 1,255 controls, Carrasquillo et al. (2009) found an association between AD and rs5984894 in the PCDH11X gene (300246) on chromosome Xq21.3 (p = 5.7 x 10(-5)). The findings were replicated in 4 additional series comprising 1,547 cases and 1,209 controls, yielding a combined p value of 3.9 x 10(-12). Odds ratios were 1.75 for female homozygotes (p = 2.0 x 10(-7)) and 1.26 for female heterozygotes (p = 0.01) compared to female noncarriers. The odds ratio was 1.18 (p = 0.07) for male hemizygotes compared to male noncarriers. Carrasquillo et al. (2009) concluded that rs5984894 is strongly associated with late-onset Alzheimer disease in individuals of European descent from the United States.