Choline acetyltransferase G +4 A polymorphism confers a risk for Alzheimer's disease in concert with Apolipoprotein E epsilon4.

To examine whether the single nucleotide polymorphism at position +4 of the choline acetyltransferase (ChAT) confers a risk for Alzheimer's disease (AD), we determined the ChAT and the Apolipoprotein (APOE) genotypes of the 246 AD patients and 561 non-demented controls. The ChAT AA genotype was found to confer the risk for AD in concert with the APOE epsilon4 by stochastic search variable selection (SSVS) approach. The odds of the ChAT AA for AD were 3.25 (95% CI = 1.17-9.03). The mean ages-at-onset of AD were lower in those carrying the ChAT AA than those carrying the ChAT AG or ChAT GG, regardless to the occurrence of the APOE epsilon4. The ChAT AA is a novel genetic risk factor AD, and the SSVS is a useful approach for analyzing association with multiple candidate genes simultaneously.