Convergent evidence that choline acetyltransferase gene variation is associated with prospective smoking cessation and nicotine dependence.
The ability to quit smoking is heritable, yet few genetic studies have investigated prospective smoking cessation. We conducted a systems-based genetic association analysis in a sample of 472 treatment-seeking smokers of European ancestry after 8 weeks of transdermal nicotine therapy for smoking cessation. The genotyping panel included 169 single-nucleotide polymorphisms (SNPs) in 7 nicotinic acetylcholine receptor subunit genes and 4 genes in the endogenous cholinergic system. The primary outcome was smoking cessation (biochemically confirmed) at the end of treatment. SNPs clustered in the choline acetyltransferase (ChAT) gene were individually identified as nominally significant, and a 5-SNP haplotype (block 6) in ChAT was found to be significantly associated with quitting success. Single SNPs in ChAT haplotype block 2 were also associated with pretreatment levels of nicotine dependence in this cohort. To replicate associations of SNPs in haplotype blocks 2 and 6 of ChAT with nicotine dependence in a non-treatment-seeking cohort, we used data from an independent community-based sample of 629 smokers representing 200 families of European ancestry. Significant SNP and haplotype associations were identified for multiple measures of nicotine dependence. Although the effect sizes in both cohorts are modest, converging data across cohorts and phenotypes suggest that ChAT may be involved in nicotine dependence and ability to quit smoking. Additional sequencing and characterization of ChAT may reveal functional variants that contribute to nicotine dependence and smoking cessation.
Ray
Riju
R
Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA.
Mitra
Nandita
N
Baldwin
Don
D
Guo
Mengye
M
Patterson
Freda
F
Heitjan
Daniel F
DF
Jepson
Christopher
C
Wileyto
E Paul
EP
Wei
Jinxue
J
Payne
Thomas
T
Ma
Jennie Z
JZ
Li
Ming D
MD
Lerman
Caryn
C
D000109:Acetylcholine / Q000378:metabolism; D000328:Adult; D001923:Brain Chemistry / Q000235:genetics*; D002795:Choline O-Acetyltransferase / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D021122:Protein Subunits / Q000235:genetics; D011978:Receptors, Nicotinic / Q000235:genetics; D016540:Smoking Cessation / Q000523:psychology*; D014029:Tobacco Use Disorder / Q000201:enzymology* / Q000235:genetics*; D044465:White People
D005819:Genetic Markers; D021122:Protein Subunits; D011978:Receptors, Nicotinic; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine