RESUMEN
<p><b>OBJECTIVE</b>To study the relationship between 637A/G gene polymorphisms of the transporter associated with antigen processing 1 gene and nasopharyngeal carcinomas (NPC) and to find out the susceptible genes of NPC in Han population in Yunnan Province, China.</p><p><b>METHODS</b>Two hundred and thirty-three cases with NPC and 296 cases matched cancer-free controls were genotyped for the TAP1 637A/G polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Epstein-Barr virus infection was detected by PCR. The adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated by using unconditional logistic regression model.</p><p><b>RESULTS</b>Contrast with homozygous TAP1 637 AA, G allele significantly increasing risk of NPC was associated with homozygous 637 GG OR = 4.26 (95%CI were 2.08 - 8.66, P < 0.001) and heterozygous 637 AG OR = 1.56 (95%CI were 1.12 - 2.33, P < 0.05). The subjects at least having one TAP1 637 G allele had OR of 1.88 (95%CI were 1.35 - 2.82, P < 0.001). Furthermore, EBV infection may increase the risk of developing NPC interacting with TAP1 637 A/G polymorphism OR = 2.76(95% CI were 1.69 - 4.63, P < 0.001).</p><p><b>CONCLUSIONS</b>The TAP1 637G allele is associated with the NPC in Han population in Yunnan China, EBV pathogenesis in NPC might be facilitated by polymorphisms in the TAP1 proteins.</p>