A novel CYP2D6 allele with an abolished splice recognition site associated with the poor metabolizer phenotype.

A novel loss-of function allele of the CYP2D6 gene was characterized in a PM individual using exon-by-exon PCR-SSCP analysis. This allele, we termed CYP2D6(F), harbours four mutations including a new mutation (D6-F) which abolishes the splice acceptor site of the 1st intron and results in a premature stop codon. DNA samples from a large population of healthy unrelated volunteers were tested for D6-F using a PCR-assay we developed for the specific identification of the mutation in genomic DNA. The prevalence of D6-F was very low. However, its identification combined with that of the previously reported gene inactivating mutations would further increase the phenotype prediction rate by genotyping.