To investigate whether methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and erythrocyte concentration of methotrexate (EMTX) could serve as predictors of methotrexate (MTX) efficacy and toxicity in patients with juvenile idiopathic arthritis (JIA).
To study the relationship of C677T and A1298C polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene to toxicity and efficacy of methotrexate (MTX) in patients with juvenile idiopathic arthritis (JIA).