Association of MICA-A5.1 allele with susceptibility to celiac disease in a family study

OBJECTIVE: The aim of this study was to analyze the role of the major histocompatibility complex class I chain-related gene A (MICA) transmembrane polymorphism in celiac disease (CD) susceptibility. METHODS: Sixty-one celiac Spanish families were genotyped for MICA transmembrane polymorphism by a polymerase chain reaction method combined with fluorescent technology. A transmission disequilibrium test was performed to investigate the preferential transmission of MICA alleles to the affected offspring. RESULTS: The MICA A5.1 allele was shown to be significantly transmitted to the affected siblings. This association was independent of the CD-predisposing DQ2 haplotype. Additionally, we classified our celiac families into typical and atypical groups as we found a significant association with MICA A5.1 in typical celiac families. There was also an association tendency with atypical families. CONCLUSIONS: Our data suggest that the MICA A5.1 allele is associated with CD development independently of DQ2-extended haplotype and clinical forms of CD.