rs1803274

The rs1803274(A) allele encodes a version of the butyrylcholinesterase enzyme known as the K variant; it may also be known as CHE*539T or BCHE*539T. The allele produces a 30% reduction in serum butyrylcholinesterase activity, and it is often co-inherited with the SNP encoding the so-called "atypical" butyrylcholinesterase, rs1799807. Although not replicated by other studies, some studies have found, at least in certain populations, a possible association between this SNP and risk for Alzheimer's disease (independent of ApoE4 status): * reports ~2x increased Alzheimer's risk for carriers of one or more rs1803274(A) alleles, based on a study of 135 Canadian patients * reports ~3.5x increased Alzheimer's risk for carriers of one or more rs1803274(A) alleles, based on a study of 175 patients from Northern Ireland * : reports an association this SNP and Alzheimer-related neuropathology, but only for K variant homozygotes, and was limited to at ages > or = 70 years but not 50-69 years, based on 521 cases. Related studies include: * reports that rs1803274(A;A) homozygotes (i.e. K variant homozygotes), but not heterozygotes, are at higher risk factor for developing neurofibrillary tangles, at least in young individuals Childhood brain tumors, residential insecticide exposure, and pesticide metabolism genes.