TAP POLYMORPHISM IN PATIENTS WITH BEHCETS-DISEASE

Objective-To determine if susceptibility to Behcet's disease (BD) is associated with polymorphism of HLA-DRB1, HLA-DQB1, and TAP1 and TAP2 genes, Methods-Fifty eight Spanish BD patients and 116 ethnically matched unrelated healthy subjects were typed at the HLA-DRB1 and HLA-DQB1 loci using polymerase chain reaction/sequence specific oligotyping (PCR/SSO). TAP1 and TAP2 alleles were assigned using amplification refractory mutation system-PCR. Results-TAP1C was absent in BD patients, but was found in 12.1% of control subjects (p(corr) < 0.05; relative risk = 0.06). Additionally, a linkage disequilibrium between HLA-DQB1*0501 and TAP2B was observed in BD patients (Delta = 0.095, p(corr) < 0.02), but not in the control group (Delta = -0.0031, p > 0.05). Conclusions-The complete absence of TAP1C alleles in BD patients may indicate that TAP1 polymorphism is not without some significance in the development of BD. Furthermore, the existence of a linkage disequilibrium between HLA-DQB1*0501 and TAP2B in our patients suggests that the gene conferring susceptibility for BD is inherited as an extended haplotype in the population studied.