High prevalence of CYP2A6⁎4 and CYP2A6⁎9 alleles detected among a Malaysian population

BackgroundCYP2A6 gene encodes the principal enzyme involved in the metabolism of many drugs including artesunate. We developed a simplified duplex nested PCR method for the detection of the CYP2A6⁎1B, CYP2A6⁎2, CYP2A6⁎4, CYP2A6⁎7, CYP2A6⁎8 and CYP2A6⁎9 variant alleles highly prevalent among Malaysian population.MethodsGenomic DNA was isolated from peripheral blood of patients treated with artesunate by using a DNA extraction kit. Fragments from TATA box in 5′ flanking region, exons 1 to 4 and exon 8 to 3′ UTR of the gene were amplified using a first PCR step (PCR1). Products from PCR1 were then used to run a duplex PCR (PCR2) for detecting the selected variant alleles.ResultsAll 6 CYP2A6 alleles were successfully amplified and confirmed by sequencing. The frequency of the alleles were 14.6% for CYP2A6⁎1B, 16.7% for CYP2A6⁎4, 4.2% for CYP2A6⁎8 and 10.4% for CYP2A6⁎9.ConclusionHigh frequencies of the CYP2A6⁎4 and CYP2A6⁎9 alleles which contribute to the poor metabolism status may impact treatment of patients receiving drugs metabolized by CYP2A6 such as artesunate among Malaysians.