Failure to confirm a synergistic effect between the K-variant of the butyrylcholinesterase gene and the ε4 allele of the apolipoprotein gene in Japanese patients with Alzheimer's disease

To confirm a synergistic effect between the polymorphic K variant of the butyrylcholinesterase (BChE-K) gene and the ε4 allele of the apolipoprotein E (APOE) gene in Alzheimer's disease, the frequency of the BChE-K allele was re-examined in a large series of Japanese patients with Alzheimer's disease and controls. hundred and three patients Alzheimer's disease and 288 age and sex matched controls were genotyped by polymerase chain reaction and restriction fragment Length polymorphism for BChE-K and APOE. No changes were found in the frequency of BChE-K, either in the Alzheimer's disease group as a whole (0.17 v 0.14; p = 0.36) or in early (0.16 v 0.16; p=0.98) or late (0.17 v 0.13; p=0.24) onset patients compared with age matched controls. The study failed to confirm the findings of a previous study which found a significantly higher incidence of BChE-K in patients with Alzheimer's disease with APOE ε4 allele than in controls. In the Japanese population studied here, there was no association between BChE-K and Alzheimer's disease, nor an interaction between BChE-K and APOE ε4 allele.