The P86L common allele of CALHM1 does not influence risk for Alzheimer disease in Japanese cohorts.

A common P86L variant in CALHM1 was recently identified to increase susceptibility to Alzheimer disease (AD) in individuals of European-descent. To determine whether or not this association is also valid in a different ethnic population, we directly sequenced three nearby SNPs including P86L in more than 2,500 Japanese AD case-control samples. We found no association between CALHM1 P86L polymorphism and AD risk in Japanese individuals. We also found a small number of non-synonymous minor variants in both control and case populations, some of which are predicted to affect protein function, but are unlikely to increase this risk of AD in this population. We also determined that the P86L allele frequency is lower in non-Caucasian populations than in Caucasians. Our findings suggest that the CALHM1 P86L common variant may not influence AD risk in Japanese. (c) 2009 Wiley-Liss, Inc.