Identification of CYP2B6 sequence variants by use of multiplex PCR with allele-specific genotyping.
BACKGROUND
Cytochrome P450 2B6 (CYP2B6) has a role in the metabolism of many clinically important substances, but the variation within the CYP2B6 gene has not been fully characterized. The aim of the present study was to develop a reliable and robust assay for determining genotypic variants.


METHODS
We used a two-stage procedure. An initial multiplex PCR reaction amplified the relevant gene fragments in exonic and regulatory regions to ensure isolation of CYP2B6 from its similar pseudogene (CYP2B7). This product was then genotyped by allele-specific PCR.


RESULTS
The assay detected the following published single-nucleotide polymorphisms: C64T (Arg22Cys), C78T, G216C, G516T (Gln172His), C777A (Ser259Arg), A785G (Lys262Arg), and C1459T (Arg487Cys), as well as additional loci found within the single-nucleotide polymorphism (SNP) databases: A1190G, C1268A, C1330T, A1382G, A1402T, and an A/T SNP in intron 2 (A12917T). This approach detected all common, previously reported alleles and identified a new allele (CYP2B6*4C) present in 2.2% of a Caucasian population. Genotypic frequencies obtained were consistent with previously published results.


CONCLUSIONS
This method is simple, reliable, rapid, and amenable to automation and could facilitate the large-scale genotypic analysis of CYP2B6.
Jacob
Robyn M
RM
Cancer Research UK General Practice Research Group, Department of Clinical Pharmacology, University of Oxford, Oxford, United Kingdom.
Johnstone
Elaine C
EC
Neville
Matt J
MJ
Walton
Robert T
RT
D000483:Alleles; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D065702:Cytochrome P-450 CYP2B6; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics; D000072467:Cytochrome P450 Family 2; D005787:Gene Frequency; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D010089:Oxidoreductases, N-Demethylating / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D020641:Polymorphism, Single Nucleotide
D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases; C585599:CYP2B6 protein, human; C107082:CYP2B7P protein, human; D065702:Cytochrome P-450 CYP2B6; D000072467:Cytochrome P450 Family 2; D010089:Oxidoreductases, N-Demethylating