Possible association between genetic variants in the H2AFX promoter region and risk of adult glioma in a Chinese Han population

Abstract

H2AFX, a histone H2A gene family member X, is a key component in the detection of and response to DNA double-strand breaks (DSBs) caused by ionizing radiation (IR), a known risk factor for glioma. Thus, genetic variants in the H2AFX promoter region that may result in abnormal protein expression could confer susceptibility to glioma. In this case-control study, we genotyped three common single-nucleotide polymorphisms (SNPs) (rs643788, rs8551, and rs2509851) in the H2AFX promoter region in 669 adult glioma patients and 638 cancer-free controls. The associations between each SNP or haplotype and glioma risk were estimated by calculating odds ratios (ORs) and the corresponding 95% confidence interval (CI) using unconditional logistic regression models, with adjustment for age and sex. The H2AFX rs643788 A variant genotypes were significantly associated with reduced risk of glioma (GA versus GG: adjusted OR = 0.72, 95% CI = 0.56-0.94; GA/AA versus GG: adjusted OR = 0.75, 95% CI = 0.59-0.94), compared with the common GG genotype. Furthermore, this decreased risk was more evident among those aged ≥ 45 years (adjusted OR = 0.64, 95% CI = 0.45-0.90), male subjects (adjusted OR = 0.70, 95% CI = 0.50-0.96), and patients with glioblastoma (adjusted OR = 0.66, 95% CI = 0.46-0.94). These results suggest that a common variant in the H2AFX promoter region may modulate risk of glioma, particularly for adult glioma. However, our findings need to be replicated in other independent populations.