Small ubiquitin-like modifier 4 (SUMO4) is involved in a range of autoimmune diseases and is known to downregulate the transcription activity of nuclear factor kappa B (NF-κB). Our objective was to investigate the association of a certain polymorphism (C438T) of the SUMO4 gene with Behet's disease (BD) in terms of its incidence and clinical features in Korean patients. We consecutively enrolled 83 patients with BD and 120 healthy controls. Genomic DNA was extracted from whole-blood samples. We identified a single nucleotide change (C438T) in the SUMO4 gene using an amplification refractory mutation system (ARMS) technique. To validate the ARMS technique, we compared its results to the results of direct sequencing in 20 subjects. HLA-B51 status was determined by polymerase chain reaction sequence-specific primers. The presence of papulopustular lesions (P = 0.006) and vascular involvement (P = 0.045) was significantly different between C438T genotypes in HLA-B51-positive patients with BD. There were no differences in allelic or genotypic frequencies of the SUMO4 C438T polymorphism between patients with BD and controls (P = 0.567 and P = 0.818, respectively). The difference in papulopustular skin lesions between CC and CT + TT genotypes in HLA-B51-positive patients with BD was also statistically significant (P = 0.002, OR = 23.40, 95% CI: 2.33-235.54). The C438T polymorphism in the SUMO4 gene is associated with significantly increased risk of papulopustular skin lesions in HLA-B51-positive patients.

Small ubiquitin-like modifier 4 (SUMO4) is involved in a range of autoimmune diseases and is known to downregulate the transcription activity of nuclear factor kappa B (NF-κB). Our objective was to investigate the association of a certain polymorphism (C438T) of the SUMO4 gene with Behet's disease (BD) in terms of its incidence and clinical features in Korean patients. We consecutively enrolled 83 patients with BD and 120 healthy controls. Genomic DNA was extracted from whole-blood samples. We identified a single nucleotide change (C438T) in the SUMO4 gene using an amplification refractory mutation system (ARMS) technique. To validate the ARMS technique, we compared its results to the results of direct sequencing in 20 subjects. HLA-B51 status was determined by polymerase chain reaction sequence-specific primers. The presence of papulopustular lesions (P = 0.006) and vascular involvement (P = 0.045) was significantly different between C438T genotypes in HLA-B51-positive patients with BD. There were no differences in allelic or genotypic frequencies of the SUMO4 C438T polymorphism between patients with BD and controls (P = 0.567 and P = 0.818, respectively). The difference in papulopustular skin lesions between CC and CT + TT genotypes in HLA-B51-positive patients with BD was also statistically significant (P = 0.002, OR = 23.40, 95% CI: 2.33-235.54). The C438T polymorphism in the SUMO4 gene is associated with significantly increased risk of papulopustular skin lesions in HLA-B51-positive patients.