Loukola et al Linkage of nicotine dependence and smoking behavior on 10q, 7q and 11p in twins with homogeneous genetic background. The Pharmacogenomics Journal (2008) vol 8, 209–219
Why do some people tolerate and become dependent upon smoking tobacco and others do not. It important to study the genetic determinants of smoking behavior and the key factor sustaining compulsive smoking, that is, nicotine dependence (ND). Loukola et al looked at the genetic background of smoking in a special study sample of twins, equivalent for early life events and for smoking from the nationwide twin cohort of the genetically unique population of Finland. The twins and their families were examined for extensive phenotype profiles and a genome-wide scan was performed to identify loci behind the smoking status, ND and the comorbid phenotype of ND and alcohol use in 505 individuals from 153 families. They replicated previous linkage findings on 10q (max logarithm of the odds (LOD) 3.12) for a smoker phenotype, and on 7q and 11p (max LOD 2.50, and 2.25, respectively) for the ND phenotype. The loci linked for ND also showed evidence for linkage for the comorbid phenotype. Their study provides confirmatory evidence for the involvement of these genome regions in the genetic etiology of smoking behavior and ND and for the first time associates drinking and smoking to a shared locus on 10q.
nicotine dependence, smoking, alcohol use, genome-wide scan, twin, linkage
- Martin Eastwood