Limited effects of frequent CYP2D6*36-*10 tandem duplication allele on in vivo dextromethorphan metabolism in a Japanese population

作者：Kiyotani Kazuma; Shimizu Makiko; Kumai Toshio; Kamataki Tetsuya; Kobayashi Shinichi; Yamazaki Hiroshi^*

来源：European Journal of Clinical Pharmacology, 2010, 66(10): 1065-1068.

DOI：10.1007/s00228-010-0876-4

• P450 2D6
• Copy number variation
• Allelic copy number
• Japanese

Although CYP2D6*36 was thought to be one of the alleles causing the poor metabolizer phenotype, several in vitro studies clarified that the enzyme produced by CYP2D6*36 showed enzymatic activities. However, the effects of CYP2D6*36 in tandem with CYP2D6*10 on the in vivo CYP2D6 activity have been unclear. In this study, we investigated in vivo metabolic capacities of CYP2D6 among the subjects carrying different numbers of CYP2D6*36 in tandem with CYP2D6*10.
We measured the metabolic ratio (MR) of dextromethorphan in 98 subjects. We determined the CYP2D6 genotype of these subjects, including allelic copy number of CYP2D6*10 and CYP2D6*36 by direct sequencing, TaqMan assay, and real-time Invader assay.
Single copies of CYP2D6*10 and tandem duplication of CYP2D6*36-*10 alleles were found at frequencies of 8.7 and 32.7%, respectively. Median dextromethorphan MRs of the subjects carrying CYP2D6*10 and CYP2D6*36-*10 were not significantly different (P = 0.24).
CYP2D6*36 in tandem with CYP2D6*10 plays a minor role in interindividual variation of dextromethorphan metabolism in vivo.

• 出版日期2010-10