Journal of Diabetes and Metabolic Disorders11STRONG LINKAGE BETWEEN TYPE 1 DIABETES AND THE DRB1LYS71+ ALLELE IN 81 DANISH DIABETIC FAMILIES..4150MehdiZamaniJeanNeijrupJean-JacquesKasmian20151005Background: Numerous studies have confirmed the association between type 1 diabetes mellitus (DM1) and polymorphisms of HLA genes on chromosome 6p21. Controlled DNA studies in Belgium recently have found a statistically significant association between DM1 and certain HLA class II genes, especially DRB1Lys71+. Methods: 81 Danish families (each with at least 2 members with DM1) and 82 healthy controls were assessed for HLA polymorphisms. 54 of the 81 diabetic families were also assessed for polymorphisms at the HLA-B-DQB1, HLA-B-DQA1, and TNF-A and TNF-B loci. Affected sib-pair analysis was used to study correlation between DM1 and DRB1 alleles encoding Lys71+. Results: Homozygous expression of DRB1Lys71+ carried a relative risk (RR) of 103.5 for DM1. There was a very strong correlation (p<1×10-6) between DM1 and DRB1 alleles encoding Lys71+. Family-based association studies showed that DRB1Lys71+ was the most important determinant of DM1 in carriers (haplotype relative risk = 8.38). Haplotype analysis confirmed this. Conclusion: The DRB1Lys71+ allele confers genetic predisposition to DM1 most strongly of all.https://jdmd.tums.ac.ir/index.php/jdmd/article/view/15