Background and objective: Glutathione S-transferase M1 (GSTM1) deficiency may increase the risk of nasopharyngeal carcinoma (NPC). This study was to evaluate the correlation of the single nucleotide polymorphism (SNP) in the coding region of GSTM1 gene to NPC susceptibility in southern China population.
Methods: In total 239 NPC patients and 286 age-matched healthy controls were entered into the study. Among them, 225 out of 239 NPC patients and 273 out of 286 controls were used for statistical analysis. SNP screening of all exons, relevant intron-exon boundaries, and the promoter region of GSTM1, in total 4739bp, was performed by PCR direct sequencing. The loci T1270533G and C1256088C were selected for the case-control study using the tetra-Primer ARMS-PCR, as well as the sequencing method.
Results: In total 29 SNPs of GSTM1 were identified by sequencing. Missense mutation occurred in the polymorphic loci of T1270533G and C1256088C. However, no evident relationships between the variants of T1270533G and clinical phenotypes of NPC were observed in the NPC group and healthy control group (OR = 0.170, 95%CI = 0.95-0.306 for homozygote TT). The deletion frequency of C1256088C was 45% (45/100) for NPC patients and 42% (42/100) for controls.
Conclusions: The polymorphism of T1270533G does not affect the detoxification function of GSTM1. The T1270533G locus has no apparent association with genetic susceptibility to NPC in the southern China population. The loss rate of C1256088C is high in this study.