Abstract
The cytochrome P450 CYP2D6 is a polymorphic enzyme, for which 5%–10% of Caucasians (poor metabolizers) lack activity. The majority of mutations giving rise to the deficiency have now been identified but some individuals show anomalous phenotype-genotype relationships when screened for the common mutant alleles. We have sequenced all nine exons and intron-exon boundaries in a subject who was phenotypically a poor metabolizer but genotypically heterozygous when screened for the common alleles. A single base-pair deletion (T1795) was detected in exon 3 and a base substitution (G2064A) resulting in an amino acid substitution (G212E) in exon 4. The deletion results in premature termination of translation and a truncated protein. In a group of 50 white Americans, the allele frequency for the new mutant allele was 0.01. The new allele explains some cases of anomalous genotype/phenotype relationships for CYP2D6.
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Daly, A.K., Leathart, J.B.S., Idle, J.R. et al. An inactive cytochrome P450 CYP2D6 allele containing a deletion and a base substitution. Hum Genet 95, 337–341 (1995). https://doi.org/10.1007/BF00225204
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DOI: https://doi.org/10.1007/BF00225204