FREQUENCY OF GSTM1 AND GSTT1 GENE POLYMORPHISMS IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA AND THEIR ASSOCIATION WITH HEMATOLOGICAL PARAMETERS

Abstract

Background: Genetic polymorphisms of Glutathione S-transferase Mu 1 (GSTM1) and Glutathione S-transferase Theta 1 (GSTT1) have been associated with altered detoxification capacity and may contribute to the development of childhood acute lymphoblastic leukemia (ALL).

Objective: To determine the frequency of GSTM1 and GSTT1 polymorphisms among children with ALL and evaluate their association with hematological parameters.

Methods: A Case-control study was conducted among 45 children with ALL cases and 45 healthy controls. GSTM1 and GSTT1 genotypes were detected using multiplex polymerase chain reaction (PCR) with β-globin as an internal control. PCR amplification was performed using 2× EasyTaq® PCR SuperMix (TransGen Biotech, UK). The observations on hematological parameters such as hemoglobin, total leukocyte count, platelet count and differential leukocyte count were obtained and analyzed.

Results: A total of 90 participants (45 ALL patients and 45 healthy controls) were included in the study. Hematological abnormalities typical of leukemia were seen in ALL patients with increased WBC, blast and decreased Hb and platelet levels (p < 0.05) when compared to controls. With regards to genetic analysis, the GSTM1 null genotype was significantly associated with childhood ALL susceptibility (p = 0.027), while the GSTT1 null genotype showed a borderline, non-significant association with childhood ALL susceptibility (p = 0.056). In subgroup analysis, GSTT1 showed significant associations, which implies that it may be involved in disease presentation instead of overall disease susceptibility.

Conclusion: There was a significant association between GSTM1 null genotype and childhood ALL, but not for GSTT1 which had only a weak, non-significant association. No consistent association was found between the GST polymorphisms and the hematological parameters, but in the case of GSTT1, significant association was observed with blast percentage and easy bleeding in the subgroup analysis.