Association between butyrylcholinesterase K variant and mild cognitive impairment in the Thai community-dwelling patients

Natsalil Pongthanaracht,1 Somchai Yanarojana,1 Darawan Pinthong,1 Supeenun Unchern,1 Amnuay Thithapandha,1 Prasert Assantachai,2 Porntip Supavilai11Department of Pharmacology, Faculty of Science, 2Department of Preventive and Social Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, ThailandObjective: To study the association of the butyrylcholinesterase K variant (BChE-K) and the plasma BChE activity with mild cognitive impairment (MCI) in Thai community-dwelling patients.Methods: One hundred patients diagnosed with MCI and 100 control subjects were recruited from the community-dwelling setting in Bangkok, Thailand. The genotype and allele distributions of the BChE-K were determined by polymerase chain reaction and subsequent DNA sequencing. The BChE activity was measured in plasma according to the Ellman’s method.Results: The BChE-K allele frequencies in the Thai community-dwelling patients were in accordance with other ethnics. The BChE-K allele frequency in the control subjects (12%) was higher than that of MCI patients (5.5%), suggesting a protective role of BChE-K for MCI in the Thai community-dwelling patients. The BChE-K homozygotes were significantly associated with lower BChE activity.Conclusion: Our results suggested that the BChE-K may be implicated as a protective factor for MCI in the Thai community-dwelling patients, although a further study with a large sample size is warranted to confirm this.Keywords: butyrylcholinesterase K variant, butyrylcholinesterase activity, mild cognitive impairment, Thai community-dwelling patient