||One copy of CYP2A6*5 non-functioning variant; impaired nicotine metabolism
||Two copies of CYP2A6*5 non-functioning variant; impaired nicotine metabolism
rs5031017 in the CYP2A6 gene, also known as G479V, 1436G>T or 6582G>T, the T allele indicates the CYP2A6*5 inactive form of the gene.
[PMID 21205058] reports that poor metabolizers (such as those with inactive forms of CYP2A6), among male smokers and compared to normal smokers, smoked fewer cigarettes, took longer to smoke regularly, and if they had stopped smoking, waited a shorter period of time before making the decision. Unfortunately, this group also had a lower likelihood of smoking cessation.