Abstract: OBJECTIVE: To determine the association of TNF-A rs1800629 and rs361525 polymorphism and haplotypes with the susceptibility of gastric cancer in Uygur and Han ethnic groups in Xinjiang. METHODS：Snapshot method was used for the polymorphism of TNF-A gene in 322 cases of gastric cancer (93 Uygur ethnic group，229 Han ethnic group) and 487 controls (231 Uygurs，256 Hans) in Xinjiang area. Haplotypes distribution was estimated by the SHEsis software. Statistical differences of the genotype and haplotype frequencies between the case group and the control group were also estimated. RESULTS：In Uygur populations，allele，genotype and haplotype of TNF-A gene at rs1800629 and rs361525 site showed no significant differences between gastric cancer and control groups (P>0.05). In Han populations，there was significant difference in the frequency of TNF-A gene at rs361525 site AA+GA genotype between cases and controls (χ2 = 4.56，P=0.03). The individuals with A allele had increased risk of developing GC (OR=2.41，95% CI：1.06-5.49). There was no significant difference in the frequency of TNF-A gene at rs1800629 site between gastric cancer and control group. The frequencies of TNF-A gene haplotype A-A were 0.92% and 0.86% in cases and controls，respectively，with significant difference between them (χ2=7.03，P=0.01). CONCLUSION：The genetic polymorphism of TNF-A was associated with susceptibility to gastric cancer in the Han population and this relationship varied among different ethnic groups.

Key words: gastric cancer, Uygur ethnic group, Han ethnic group, TNF-A, single nucleotide polymorphism