The frequency of the TRPC4AP haplotype in Alzheimer's patients.

A haplotype in the gene for transient receptor potential cation channel, subfamily C, member 4 associated protein (TRPC4AP), has been identified in two extended pedigrees with late-onset Alzheimer's disease. Nine of the SNPs in the haplotype were analyzed in our unrelated Alzheimer's patients and controls. The H1 haplotype was found in 36% of the patients (199 patients) and in 26% of the controls (85 controls) (P=0.0282; OR=1.56; 95%CI=1.05-2.32). The latent classification method of analysis showed that the H1 haplotype was characteristic of Alzheimer's patients, with ages-of-onset between 66 and 80 years. When clinical phenotypes were analyzed, there was a suggestion that the patients with this haplotype may have more behavioral changes and hallucinations. Moreover, both the latent classification analysis and logistic regression analysis indicated that there was no association of the haplotype with either APOE status or gender. The gene is part of a superfamily of cation channels that are involved with calcium entry into cells.