Genetic analysis of the cytochrome P-450IIC18 (CYP2C18) gene and a novel member of the CYP2C subfamily

Abstract

The CYP2C18 gene was investigated in order to characterize its molecular basis in the CYP2C subfamily. A mutation of the CYP2C18 gene was identified at the 5′-flanking region of the gene, which could be detected by digestion with DdeI. The allele frequency of the mutant CYP2C18 gene was 21.4%. Genotypes of the polymorphic DdeI site of the CYP2C18 gene were found to be completely consistent with that of the polymorphic CYP2C19 gene (the m1 mutant). The CYP2C18 and CYP2C19 genes were suggested to be linked and located close together on the chromosome. Clones containing the 5′-flanking region of a member of the CYP2C subfamily were obtained from the PCR products from human genomic DNA. The nucleotide sequence of the clone proved to be 90.5% identical to the corresponding region of the CYP2C18 gene. This is very likely to be a novel member of the CYP2C subfamily.