Nitric oxide synthase and superoxide dismutase gene polymorphisms in Behçet disease.

OBJECTIVE To investigate the association of endothelial nitric oxide synthase (NOS), inducible NOS, manganese superoxide dismutase (SOD), and extracellular SOD gene polymorphisms with susceptibility to Behçet disease (BD) in Japan. METHODS Seventy-eight consecutive Japanese patients with BD and 107 healthy control subjects were genotyped by polymerase chain reaction or polymerase chain reaction-restriction fragment length polymorphism methods for endothelial NOS polymorphisms in intron 4, exon 7, and promoter region; inducible NOS polymorphisms in exon 16 and promoter region; manganese SOD Ala16Val polymorphism; and extracellular SOD Arg213Gly polymorphism. HLA-B*51 alleles, which have been found to be associated with BD, were also determined. RESULTS The frequencies of manganese SOD Val16 increased significantly in patients with BD. The manganese SOD-Val/Val genotype and HLA-B*5101 had a synergistic role in controlling susceptibility to BD. There was no significant difference in the frequencies of endothelial NOS, inducible NOS, and extracellular SOD gene polymorphisms between patients with BD and control subjects. CONCLUSION The manganese SOD Val16 allele is associated with the development of BD in Japan. Extracellular SOD, endothelial NOS, and inducible NOS gene polymorphisms do not constitute a risk factor for developing BD in Japan. CLINICAL RELEVANCE The manganese SOD gene polymorphism seems to contribute to BD.