title: Analysis of CYP2C9*5 in Caucasian, Oriental and black-African populations.
abstract: OBJECTIVE
  CYP2C9 is a polymorphic gene with at least six known allelic variants (CYP2C9*1 to *6). CYP2C9*5 has been recently described in African-Americans. The lower activity of CYP2C9*5 encoded enzyme than *1 has been reported for the S-warfarin 7-hydroxylation in vitro. The aim of the present study was to develop an assay for the analysis of this variant and to determine the frequency of this polymorphism in different ethnic populations.
  
  
  METHODS
  A PCR-based endonuclease digestion method, using a mismatched forward primer that introduced a recognition site for AvaII in all the CYP2C9 genotypes except CYP2C9*5, is described. DNA samples from 150 Ethiopians, 183 Tanzanians, 200 Caucasians from Sweden and 150 Orientals from Korea were screened for this variant allele.
  
  
  CONCLUSIONS
  The CYP2C9*5 allele was analysed using a polymerase chain reaction-based endonuclease method, and it was found in three Tanzanians (allele frequency, 0.0082) but not in Ethiopians, Caucasians or Orientals.
authors.affiliation: Department of Medical Laboratory Sciences and Technology, Division of Clinical Pharmacology, Karolinska Institutet at Huddinge University Hospital, Stockholm, Sewden. uyasar@hacettepe.edu.tr
authors.forename: Umit
authors.initials: U
authors.lastname: Yasar
authors.forename: Eleni
authors.initials: E
authors.lastname: Aklillu
authors.forename: Roberto
authors.initials: R
authors.lastname: Canaparo
authors.forename: Mia
authors.initials: M
authors.lastname: Sandberg
authors.forename: Jane
authors.initials: J
authors.lastname: Sayi
authors.forename: Hyung-Keun
authors.initials: HK
authors.lastname: Roh
authors.forename: Agneta
authors.initials: A
authors.lastname: Wennerholm
mesh_terms: D000595:Amino Acid Sequence; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D044466:Asian People / Q000235:genetics*; D044383:Black People / Q000235:genetics*; D065729:Cytochrome P-450 CYP2C9; D004247:DNA / Q000032:analysis; D005787:Gene Frequency / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D017354:Point Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D018807:Polymorphism, Single-Stranded Conformational; D017422:Sequence Analysis, DNA; D044465:White People / Q000235:genetics*; D001741:Black or African American
chemical_list: D004247:DNA; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases