Lack of association of MICA transmembrane region polymorphism and Behcet'sdisease in Spain

We have analyzed the distribution of the major histocompatibility complex ( MHC) class I chain-related gene A (MICA) transmembrane alleles among 58 Spa nish patients with Behcet's disease (BD) and in 194 ethnically matched heal thy controls. The study included the characterization of A4, A5, A5.1, A6 " new" and "old" and A9 MICA-TM alleles using polymerase chain reaction. As p reviously reported, the serological B51 specificity was increased among thi s ED patient group (36.25% vs. 19.6% in controls; P=0.009; OR=2.33). The MI CA-TM alleles A6 ("new" and "old"), in linkage disequilibrium with HLA-B51 and HLA-B14 respectively, were only slightly increased among patients (70.7 % vs, 61.3% in controls; P=NS), We conclude that, in contrast to previous f inding reporting a strong association of MICA-TM genes and Behcet disease i n Japanese patients, in our population HLA-B51 is more closely associated t o Behcet susceptibility than MICA TM genes. Finally, our data show that in Spain, as occurs in other populations, some MICA-TM alleles exhibit strong linkage disequilibrium with certain alleles of the HLA-B locus.