Analysis of CYP2C9*5 in Caucasian, Oriental and black-African populations.
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.
Yasar
Umit
U
Department of Medical Laboratory Sciences and Technology, Division of Clinical Pharmacology, Karolinska Institutet at Huddinge University Hospital, Stockholm, Sewden. uyasar@hacettepe.edu.tr
Aklillu
Eleni
E
Canaparo
Roberto
R
Sandberg
Mia
M
Sayi
Jane
J
Roh
Hyung-Keun
HK
Wennerholm
Agneta
A
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
D004247:DNA; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases