Genetic polymorphism of the hepatic cytochrome P450 2C19 in north Indian subjects.
One hundred unrelated healthy North Indian subjects were phenotyped with respect to their ability to metabolize omeprazole to 5-hydroxyomeprazole. Each volunteer was requested to ingest 20 mg (57.9 mumol) omeprazole. Urine was collected for a period of 8 hours and the amount of 5-hydroxyomeprazole excreted was estimated by HPLC. Histogram, probit, and normal test variable plots showed the antimode value for the log hydroxylation index of omeprazole to be 1.7. Of 100 North Indian subjects, 11 demonstrated log hydroxylation index values more than 1.7. Thus it is inferred that the frequency of occurrence of poor metabolizers of omeprazole in North Indian subjects is 11% (95% confidence interval, 5% to 17%). From the Hardy-Weinberg Law it was computed that the frequency of occurrence of the mutant allele of hepatic CYP2C19 in the North Indian subjects was 0.33.
Lamba
J K
JK
Department of Biochemistry, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Dhiman
R K
RK
Kohli
K K
KK
D000328:Adult; D001189:Aryl Hydrocarbon Hydroxylases; D065731:Cytochrome P-450 CYP2C19; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D004791:Enzyme Inhibitors; D005260:Female; D006801:Humans; D006900:Hydroxylation; D007194:India; D008297:Male; D008875:Middle Aged; D006899:Mixed Function Oxygenases / Q000235:genetics*; D009853:Omeprazole; D010641:Phenotype; D011110:Polymorphism, Genetic; D044465:White People / Q000235:genetics*
D004791:Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D009853:Omeprazole