Association of small ubiquitin-like modifier 4 (SUMO4) polymorphisms in a Tunisian population with Behcet's disease

Objectives. An association of SUMO4 gene, which has recently been shown to be a negative feedback regulator for nuclear factor NF-kappa B, has been reported in several autoimmune/inflammatory diseases. A case-control study was set up to investigate the contribution of SUMO4 locus to the genetic susceptibility to Behcet's disease (BD). Methods. One hundred and thirty-five Tunisian BD patients and 167 healthy blood donors from the same geographical area were genotyped by polymerase chain reaction for the SUMO4 polymorphisms. Results. The SUMO4+438 C allele frequency is significantly increased in BD patients (p=0.03; chi(2)=4.71; OR=1.44; 95% CI=1.02-2.04) and highly significantly increased in HLA-B51 positive BD patients (p=3 10(-6); chi(2)=21.62; OR=4.44; 95% CI=2.21-8.98). Similarly, the SUMO4 -847 G allele frequency is significantly increased in BD patients (p=0.03; chi(2)=4.34; OR= 1.41; 95% CI=1.01-1.97). The studied polymorphisms were also associated with disease severity, skin lesions and vascular involvement. Conclusion. SUMO4+438 C and -847 G alleles seem to be associated with susceptibility to BD in Tunisian population. We suggest that SUMO4 gene polymorphisms may be involved in the development of skin lesions, vascular BD, as well as the severity of the disease.