Association of the polymorphism of DR4 with the risk and severity of lumbar disc degeneration in the Chinese Han population.

OBJECTIVE Death receptor 4 (DR4), an apoptosis-associated gene, plays an important role in the pathophysiology of lumbar disc degeneration (LDD). The present study aimed to determine whether the C626G polymorphism (rs4871857) of the DR4 gene is associated with the risk and severity of LDD in the Chinese Han population. METHODS A total of 296 patients with LDD and 208 healthy controls were enrolled in this study. The grade of disc degeneration was determined according to Schneiderman's classification for MRI. The C626G polymorphism of DR4 was genotyped using polymerase chain reaction and the restriction fragment length polymorphism method. RESULTS The genotype frequency of the C626G polymorphism was in agreement with the Hardy-Weinberg equilibrium (p = 0.194). The frequencies of the 626CG and GG genotypes were higher among LDD patients compared with normal controls; however, the differences were not significant. Patients with LDD showed significantly higher frequencies of the G allele than normal controls (p = 0.023). Unconditional logistic regression analysis revealed that the G allele was significantly associated with an increased risk of LDD compared with the C allele (p = 0.025; OR 1.958; 95% CI 1.087-3.526). However, no association was found between the different genotypes and the risk of LDD. In addition, the 626CG and GG genotypes, as well as the G allele were associated with higher degenerative grades of LDD compared with the CC genotype and the C allele, respectively (p = 0.005 and p < 0.001, respectively). CONCLUSION The C626G polymorphism of DR4 may be associated with the risk and severity of LDD in the Chinese Han population.