DISTRIBUTION OF COMPOSITE CYP1A1 GENOTYPES IN AFRICANS, AFRICAN-AMERICANS AND CAUCASIANS

We present the genotype distribution of the CYP1Al gene in a sample of over 300 subjects of various ethnic origins. Genotypes are presented as composites of eight possible alleles, taking into account the three major polymorphisms, including a recently described African-American- specific MspI RFLP. A new nomenclature system is presented for clarify ing the various haplotypes. Interesting interracial differences in all elic frequencies and admixture rates were observed for the three polym orphisms, Because of the importance of the CYP1A1 gene (which encodes the aromatic hydrocarbon hydroxylase) as a biomarker of genetic suscep tibility to environmental carcinogens such as polycyclic aromatic hydr ocarbons, these data may provide a useful reference for future studies of relationships between CYP1A1 genotype and disease susceptibility.