Genetic polymorphism of CYP2D6 in the Japanese population

The frequencies of CYP2D6 mutations in a Japanese population were investiga ted. Individuals were classified into three groups: control individuals, ca ncer patients and Parkinsonians, Genotyping for CYP2D6*3, CYP2D6*4 and CYP2 D6*18 was carried out using the polymerase chain reaction, and that for CYP 2D6*5 was also carried out using XbaI restriction fragment length polymorph ism. The frequencies of the CYP2D6*3, CYP2D6*4, CYP2D6*5 and CYP2D6*18 muta nt alleles were 0%, 0.77%, 4.10% and 0.53% in more than 256 Japanese contro l individuals, respectively. Based on these data, the population frequency of the CYP2D6 poor metabolizer phenotype was estimated to be 0.29%. The dis tribution of the four mutated alleles was not significantly different betwe en control individuals and cancer patients or Parkinsonians. Pharmacogeneti cs 9:601-605 (C) 1999 Lippincott Williams & Wilkins.