Association between FAS and FASL genetic variants and risk of primary brain tumor.

The purpose of this study was to investigate whether functional polymorphisms of apoptosis pathway genes FAS and FASL are associated with the development of primary brain tumors. The study constituted 83 patients with primary brain tumor and 108 healthy individuals. In the present case-control study, the primary brain tumors were divided into two groups: gliomas and meningiomas. Evaluation of FAS -1377 G/A and FASL -844 T/C gene polymorphisms were performed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). To confirm the genotyping, results were examined by DNA sequencing method. Our results were analyzed by SPSS. The frequency of the FAS -1377 AA genotype was significantly lower in meningioma and glioma patients compared to controls (p = 0.023; p = 0.001, respectively). Multivariate logistic regression analysis revealed that FAS -1377 AA genotype was associated with decreased risk of meningioma and glioma (OR = 0.092, 95% CI: 0.012-0.719, p = 0.023 for meningiomas; OR = 0.056, 95% CI: 0.007-0.428, p = 0.006 for gliomas). However, there was no significant differences in FASL -844 T/C genotype frequencies between patients with primary brain tumors and controls (p > 0.05). In this study, combined genotypes were evaluated for association with primary brain tumors. Combined genotype analysis showed that the frequencies of AATC and AACC were significantly lower in glioma patients in comparison with those of controls (p = 0.023; p = 0.022, respectively). This study provides the first evidence that FAS -1377 AA genotype may have a protective effect on the developing primary brain tumor in a Turkish population.