Whole deletion of CYP2A6 gene (CYP2A6*4C) and smoking behavior

The relationship between nicotine metabolism of CYP2A6 and the smoking behavior in a Japanese population was investigated. The CYP2A6 genotypes were determined by the PCR method. There was a significant difference in the frequency of the CYP2A6* 4C allele, which is a whole deleted allele for the human CYP2A6 gene, between smokers and nonsmokers. The frequency of the CYP2A6* 4C allele was higher in nonsmokers than in smokers, whereas the frequency of CYP2A6* 1A/* 1B heterozygotes with a higher activity of nicotine metabolism was lower. In this study it was suggested that the CYP2A6* 4C allele may prevent the carrier from smoking and the CYP2A6* 1A/* 1B heterozygote may be at risk for developing smoking behavior. Copyright (C) 2004 S. Karger AG, Basel.