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CYP2D6 is one of the most widely investigated CYPs in relation to gene polymorphism. This study analyzed the relationship between CYP2D6 rs35742686 and rs3892097 single-nucleotide polymorphisms (SNPs) and potential risk factors in the development of acute lymphoblastic leukemia (ALL) in Kashmiri children. We recruited 300 cases and 600 controls for genotyping and risk factors assessment. Genotypes of rs35742686 and rs3892097 were analyzed by polymerase chain reaction-restriction fragment length polymorphism method. CYP2D6 expression analysis was done by quantitative reverse transcription polymerase chain reaction in ALL cases. Conditional logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI). High risk of ALL was observed in cases who carried the mutant genotypes of rs35742686 (OR = 18.15; 95% CI = 4.13-79.66, p < 0.0001) or rs3892097 (OR = 24.06; 95% CI = 10.23-56.53, p < 0.0001). Significant interaction was observed between rs35742686 and rs3892097 SNPs (P interaction = 0.001). The risk associated with the variant genotypes of rs35742686 and rs3892097 was retained in the cases whose fathers were smokers or had maternal X-ray exposure ( p < 0.001). Relative messenger ribonucleic acid expression across genotypes was significantly decreased in cases carrying rs35742686 3 (*3/*3) ( n -fold = 0.37 ± 0.156, p < 0.0079) and rs3892097 SNPs (*4/*4) ( n -fold = 0.02 ± 0.0075, p < 0.0001) suggesting these two events are independent in ALL cases. The study concluded that rs35742686 and rs3892097 SNPs are significantly associated with ALL risk in Kashmiri children.
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INTRODUCTION: Glutathione S-transferase (GST) gene deletion or polymorphic sequence variations lead to decreased enzyme activity that influences susceptibility and response to chemotherapy in acute lymphoblastic leukemia (ALL). This case-control study investigated the association of GST gene polymorphisms with the etiology and therapeutic outcome of B-ALL among Kashmiri population. METHODS: A total of 300 individuals including 150 newly diagnosed B-ALL patients and an equal number of age and gender matched controls were genotyped for five GST gene polymorphisms by polymerase chain reaction-restriction fragment length polymorphism technique (PCR-RFLP) and multiplex PCR techniques. RESULTS: Higher frequency of GSTT1 null, GSTO2-AG, and GSTO2-GG genotypes was observed in ALL cases compared to controls that associated significantly with ALL risk (GSTT1 null: OR = 2.93, p = 0.0001; GSTO2-AG: OR = 2.58, p = 0.01; GSTO2-GG: OR = 3.13, p = 0.01). GSTM1, GSTP1, and GSTO1 SNPs showed no significant association (p > 0.05). Combined genotype analysis revealed significant association of GSTT1 null/GSTM1 null (OR = 4.11, p = 0.011) and GSTT1 null/GSTP1-AG (OR = 4.93, p = 0.0003) with B-ALL susceptibility. Haplotype analysis of rs4925 and rs156697 revealed that carriers of CG haplotype had increased risk of B-ALL (p = 0.04). Kaplan-Meier plots revealed significantly inferior 3-year disease-free survival for GSTO2-GG carriers (p = 0.002). Multivariate analysis confirmed GSTO2-GG as an independent poor prognostic factor for DFS (HR = 4.5, p = 0.034). Among combined genotypes, only GSTT1 null/GSTP1-AG associated significantly with poorer DFS rates (p = 0.032). CONCLUSION: This study demonstrated that GSTT1 null individually or in combination with GSTM1null and GSTP1-AG genotypes associated with increased B-ALL risk. Also, rs156697 variant genotypes (AG and GG) associated with B-ALL, whereas the GG genotype of rs156697 influenced the treatment outcome.
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INTRODUCTION: Glutathione S-transferase (GST) gene deletion or polymorphic sequence variations lead to decreased enzyme activity that influences susceptibility and response to tyrosine kinase inhibitors in chronic myeloid leukemia (CML). We aimed to analyze relation of different GST gene sequence variants with susceptibility and response to Imatinib in CML. MATERIAL AND METHODS: A total of 150 CML cases and equal number of age and gender matched healthy controls were genotyped for five GST polymorphisms by multiplex-PCR and PCR-RFLP techniques. BCR-ABL1 transcripts were quantified by quantitative Real Time PCR (qRT-PCR). RESULTS: GSTT1, GSTO1, and GSTO2 SNPs revealed no association, while as GSTM1null genotype was observed to protect against the development of CML (OR = 0.53, P = .01). GSTP1 variant genotypes AG (OR = 2.1, P = .003) and GG (OR = 5.6, P < .001), significantly associated with increased risk of CML. Combined genotype analysis showed protective impact of GSTT1present /GSTM1null (OR = 0.44, P = .003) while as GSTT1present /GSTP1-GG (OR = 6.92, P < .001) and GSTM1present /GSTP1-GG (OR = 6.33, P < .001), significantly increased CML risk. GSTM1null genotype individually and in combination with GSTT1present associated with superior rate of major molecular response (MMR) and event free survival (EFS) (log-rank P = .029). GSTO2-AG+GG genotype associated with significantly inferior MMR rates at 3, 6, and 12 months. Also, patients with GSTO2-GG genotype showed significantly reduced EFS (log-rank P = .025). Multivariate analysis confirmed GSTM1null as a better (HR:0.19, P = .029) and GSTO2-GG genotype as an independent poor prognostic factor (HR:2.29, P = .037). CONCLUSION: GSTM1null genotype seems to have a better prognostic role while GSTP1 variants significantly increase CML risk. Also, results support a correlation between disease outcome and GSTO2 polymorphism.