title: Single-step assays to analyze CYP2D6 gene polymorphisms in Asians: allele frequencies and a novel *14B allele in mainland Chinese.
abstract: BACKGROUND
  Cytochrome P450-dependent monooxygenase 2D6 (CYP2D6) activity can be estimated by investigating the metabolism of model drugs or by genotyping the most common CYP2D6 alleles. For Caucasians, the CYP2D6 allele frequencies are well investigated, and single-step assays are available for genotyping, whereas allele analysis in mainland Chinese is limited.
  
  
  METHODS
  Two tetra-primer assays and one allele-specific amplification assay were developed to easily genotype the CYP2D6 alleles *8, *10, and *14 previously detected in Asians. Applying these assays in combination with established single-tube assays, we analyzed 223 DNA samples from Chinese volunteers for the CYP2D6 alleles *3, *4, *5, *6, *8, *10, and *14 and for duplication of CYP2D6.
  
  
  RESULTS
  Six different alleles were detected in mainland Chinese. The most frequent mutant allele was the intermediate metabolizer allele, CYP2D6*10, with a prevalence of 51.3%, followed by the poor metabolizer alleles CYP2D6*5 (7.2%) and a novel variant of CYP2D6*14. This novel *14B allele (2.0%) differs from the *14 allele by the absence of the C188T substitution and by the additional G1749C substitution. Furthermore, six duplication alleles of CYP2D6 were detected, including one duplication of the *10 allele (*10X2).
  
  
  CONCLUSIONS
  The CYP2D6 allele frequencies in mainland Chinese shows some genetic diversity compared with Chinese from other regions: a novel *14B allele, a slightly higher frequency of the *5 allele, and a slightly lower frequency of the *10 allele than in most other Chinese populations.
authors.affiliation: Institute of Clinical Chemistry, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich, Switzerland.
authors.forename: Ling
authors.initials: L
authors.lastname: Ji
authors.forename: Shixiu
authors.initials: S
authors.lastname: Pan
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Marti-Jaun
authors.forename: Edgar
authors.initials: E
authors.lastname: Hänseler
authors.forename: Katharina
authors.initials: K
authors.lastname: Rentsch
authors.forename: Martin
authors.initials: M
authors.lastname: Hersberger
mesh_terms: D000483:Alleles; D044466:Asian People / Q000235:genetics*; D002681:China; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic
chemical_list: D019389:Cytochrome P-450 CYP2D6