title: Association analysis between K and -116A variants of butyrylcholinesterase and Alzheimer's disease in a Brazilian population.
abstract: In Alzheimer's disease (AD) a reduction in acetylcholinesterase (AChE) and an increase in butyrylcholinesterase (BChE) activity are observed. K variant (539T) is the most common variant of the BCHE gene and, although controversial, several studies reported association between K variant and AD. Previous results showed that the K variant alone is not capable of diminishing BChE activity, depending on the presence of the -116A variant. Considering that, we conducted a case-control association study using a clinically well defined group of AD patients (n = 82) and age and sex matched control subjects (EC; n = 78) in order to test the association with these variations of BCHE gene in a Brazilian population. The allele, genotype and haplotype frequencies of the K and the -116A variants of BCHE gene were not significantly different between cases and controls. Although not reaching statistical significance, the results suggested that the presence of -116A variant may have a protective effect against AD. The association of the K variant with AD in a controversial manner in different surveys is probably caused by its linkage disequilibrium with -116A that, by reducing BChE activity, potentially increases cholinergic transmission in comparison with usual genotypes.
authors.affiliation: Department of Genetics, Federal University of Paraná, Curitiba, Brazil.
authors.forename: Daiane Priscila
authors.initials: DP
authors.lastname: Simão-Silva
authors.forename: Paulo Henrique Ferreira
authors.initials: PH
authors.lastname: Bertolucci
authors.forename: Roger William
authors.initials: RW
authors.lastname: de Labio
authors.forename: Spencer Luiz Marques
authors.initials: SL
authors.lastname: Payão
authors.forename: Lupe
authors.initials: L
authors.lastname: Furtado-Alle
authors.forename: Ricardo Lehtonen Rodrigues
authors.initials: RL
authors.lastname: Souza
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000201:enzymology* / Q000235:genetics*; D001938:Brazil; D002091:Butyrylcholinesterase / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D014644:Genetic Variation; D006239:Haplotypes; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male
chemical_list: D002091:Butyrylcholinesterase