HLA and Autoimmunity in North Indian Type I (Insulin-Dependent) Diabetic Multiplex Families

Summary

The HLA haplotype segregation and autoantibody spectrum in 7 type I (insulin-dependent) diabetic multiplex families of North Indian origin were determined. Of the total of 17 diabetic sibs, 7 shared both haplotypes and 3 shared one haplotype with the proband. No HLA-non-identical sibs were observed. This distribution of haplotypes was nonrandom (P ≅ 0.005). The mode of inheritance was compatible with an autosomal recessive model, while a dominant model was unlikely. Pancreatic isletcell antibodies were found in 23.5% of affected sibs, but in no healthy family member. A high incidence of other autoantibodies (parietal-cell and thyroglobulin/thyroid microsomal antibodies) was detected in both the diabetic patients (26.3%), and in healthy first-degree relatives (22.2%). These findings emphasize the role of HLA-linked genes and autoimmunity in the pathogenesis of type I diabetes in North India.

Key-Words

Type I (Insulin-Dependent) Multiplex Families - HLA - Pancreatic Islet-Cell Antibodies - Organ-Specific Antibodies