The influence of genetic RFC1, MS and MTHFR polymorphisms on the risk of acute lymphoblastic leukemia relapse in children and the adverse effects of methotrexate.

Polymorphism in genes coding drug-metabolizing enzymes may cause individual differences in the effectiveness and toxicity of many medications, including cytostatics. Although in recent years intensive treatment has positively influenced the prognosis in leukemias, many adverse effects resulting from nonspecific actions and the narrow therapeutic index of anti-cancer drugs are still observed during therapy. Determining selected gene polymorphisms may increase both the safety and the efficacy of treatment, and might help in developing individual therapies.