Major histocompatibility complex class I chain-related gene A (MICA-129) dimorphism was investigated in 73 autoimmune diabetes patients (type 1 diabetes and latent autoimmune diabetes in adults) and 75 controls from Algeria.
The aim of our study was to identify possible HLA class I and MICA alleles and conserved extended haplotypes as risk factors for the development of CD in T1D.
High-resolution SNP genotyping of the MHC was carried out in 15 type 1 diabetes (T1D) patients and 39 non-diabetic controls, homozygous for DR3-DQ2 and with one copy of the A(*)30-B(*)18-MICA(*)4-F1C30-DRB1(*)0301-DQB1(*)0201-DPB1(*)0202 HLA haplotype.
Only recognition of the MICA-4-defined middle epitope was significantly stronger in the Japanese T1D patient group compared to the Swedish T1D patients (P = 0.001).
The results from MICA and KIR studies suggest that polymorphism of these genes of the innate immune system identify possible defects in the first line of antiviral defense in the etiology of T1DM.
In conclusion, MICA is associated with type 1 diabetes in the Belgian population and the observed association does not result from the HLA-DQ associated risk.
Non-MHC genes associated with susceptibility to type 1 diabetes in both Japanese and Caucasoid patients include polymorphisms in the insulin gene, the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene, the interleukin-18 (IL18) gene and the major histocompatibility complex class I chain-related gene A (MICA) gene.
The results in this study suggest that microsatellite polymorphism within the transmembrane region of MIC-A gene is associated with genetic susceptibility to adult-onset of type 1 diabetes mellitus (T1DM), MIC-A5.1 allele, corrected P = 0.001, whereas it is not associated with latent autoimmune diabetes in adults (LADA) in Czech population.
We tested the association of MIC-A gene polymorphism with T1DM in Swedish Caucasians; if it has an age-dependent association; and if the association has an effect on gender.
In conclusion, polymorphisms in exon 5 of the MIC-A gene are associated with genetic susceptibility/protection to T1DM, but in the context of susceptibility HLA haplotypes.
Recent publications have pointed to the possibility that a second, independent susceptibility locus could be located in the same genomic region, and a triplet repeat polymorphism in exon 5 of the gene MHC class I chain-related protein A (MICA; located between TNFA and HLA-B) has been associated with several autoimmune disorders, including type 1 diabetes mellitus (DM1) and Addison's disease.
Our findings suggest that MMDM is immunogenetically different from IDDM in eastern India and that MIC-A is important in the pathogenesis of MMDM patients from Cuttack in eastern India.
The test of the strongest association of the MICA A5 allele and TNF-alpha allele 2 with IDDM showed that both are independently associated with the disease.
The aim of our study was to find the association of MIC-A alleles with IDDM, malnutrition-modulated diabetes mellitus (MMDM), and non-insulin-dependent diabetes mellitus (NIDDM) patients.
These data suggest that MICA gene is associated with age-at-onset and that a gene (or genes) responsible for age-at-onset of type 1 diabetes is located in the HLA class I region, probably near the region of MICA-B-C.
The aim of our study was to test the association of the polymorphism of the MIC-A gene with Type I (insulin-dependent) diabetes mellitus and evaluate the interaction between MIC-A and TNFA, HLA-B, HLA-DR and HLA-DQ gene polymorphism.