Association analysis of CYP2C9*3 and phenytoin-induced severe cutaneous adverse reactions (SCARs) in Thai epilepsy children

Cyp2c9 is the key enzyme in aromatic antiepileptic drugs (aeds) metabolism. cyp2c9*3 is a loss of function polymorphism. this study was designed to investigate genetic association between cyp2c9*3 and aromatic aed-induced severe cutaneous adverse reactions (scars) in thai children. the 37 aromatic aed-induced scars patients (20 phenobarbital and 17 phenytoin) and 35 tolerances (19 phenobarbital and 16 phenytoin) were enrolled. cyp2c9*3 was genotyped by allele-specific pcrs. the association between cyp2c9*3 with phenytoin-induced scars and phenobarbital-induced scars were analyzed in comparison with tolerances and healthy samples. significant association between phenytoin-induced scars and cyp2c9*3 was discovered (odds ratio=14.52; 95% confidence interval (ci)=1.18–∞, p-value=0.044). cyp2c9*3 was not associated with phenobarbital-induced scars. this study is the first report of cyp2c9*3 association to phenytoin-induced scars in thai epileptic children. the cyp2c9*3 is a reasonable predictive genetic marker to anticipate scars from phenytoin.