The Effects of Three ABCG2 Polymorphisms on Outcome of Central Nervous System Relapses in Iranian Children With Acute Lymphoblastic Leukemia Receiving High Dose Methotrexate

- Methotrexate (MTX) is the main drug for the treatment of childhood acute lymphoblastic leukemia (ALL). ABCG2 pump is the main transporter of MTX on BBB. Our aim was to investigate the possible relationship between three polymorphisms of the ABCG2 gene, and isolated CNS relapses in Iranian children with ALL receiving high dose MTX. Genotyping of three polymorphisms of the ABCG2 gene, including G34A, C376T, and C421A, was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for 56 patients. A high frequency of C376T CT genotype was observed among the patients. There was no significant association between C376T and C421 and isolated CNS relapse (P>0.05). C376T and C421A polymorphisms are not associated with isolated CNS relapse in childhood ALL.