Characterization of a novel CYP2A7/CYP2A6 hybrid allele (CYP2A6*12) that causes reduced CYP2A6 activity.

The human CYP2A6 enzyme metabolizes certain drugs and pre-carcinogens and appears to be the most important enzyme for nicotine metabolism. At present, more than 10 different allelic variants are known that cause abolished or decreased enzyme activity. Genetic polymorphism in this gene might be of particular importance for an individual's need for nicotine and for susceptibility to lung and/or liver cancer.