In conclusion, we found that the HLA-B*51 allele and the rs76546355/rs116799036 MHC SNP are independent genetic risk factors for BD in Iranians, and that positivity for the rs76546355/rs116799036 risk allele, but not for the B*51 allele, correlates with specific demographic characteristics or clinical manifestations in BD patients. The gene discussed is HLA-B; the disease is Behcet disease.