GENETIC-POLYMORPHISM OF THE HEPATIC CYTOCHROME-P450 2CL9 IN NORTH INDIAN SUBJECTS

One hundred unrelated healthy North Indian subjects were phenotyped wi th respect to their ability to metabolize omeprazole to 5-hydroxyomepr azole. Each volunteer was requested to ingest 20 mg (57.9 mu mol) omep razole. 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 subje cts, 11 demonstrated log hydroxylation index values more than 1.7. Thu s it is inferred that the frequency of occurrence of poor metabolizers of omeprazole in North Indian subjects is 11% (95% confidence interva l, 5% to 17%), From the Hardy-Weinberg Law it was computed that the fr equency of occurrence of the mutant allele of hepatic CYP2C19 in the N orth Indian subjects was 0.33.