Impaired S-mephenytoin 4'-hydroxylation is a well-described genetic polymorphism affecting drug metabolism in humans. Although ethnic differences in its distribution of polymorphism has been described, it is not known whether there is an ethnic heterogeneity of the structure and expression of the CYP2C19 enzyme in the Malaysian population.
Yang, Y. S., Wong, L. P., Lee, T. C., Mustafa, A. M., Mohamed, Z., & Lang, C. C. (2004). Genetic polymorphism of cytochrome P450 2C19 in healthy Malaysian subjects. British Journal of Clinical Pharmacology, 58(3), 332-5. https://doi.org/10.1111/j.1365-2125.2004.02144.x