Objective-To determine if susceptibility to Behcet's disease (BD) is a
ssociated with polymorphism of HLA-DRB1, HLA-DQB1, and TAP1 and TAP2 g
enes, Methods-Fifty eight Spanish BD patients and 116 ethnically match
ed unrelated healthy subjects were typed at the HLA-DRB1 and HLA-DQB1
loci using polymerase chain reaction/sequence specific oligotyping (PC
R/SSO). TAP1 and TAP2 alleles were assigned using amplification refrac
tory 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-DQB10501
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). Conclusion
s-The complete absence of TAP1C alleles in BD patients may indicate th
at TAP1 polymorphism is not without some significance in the developme
nt of BD. Furthermore, the existence of a linkage disequilibrium betwe
en HLA-DQB10501 and TAP2B in our patients suggests that the gene conf
erring susceptibility for BD is inherited as an extended haplotype in
the population studied.