Familial aggregation of LADA and juvenile type 1 diabetes in a French Caucasian family.

We describe here the unusual aggregation of diabetes cases in a family of 10 subjects. Among them, three adult siblings presented with LADA and one child presented with juvenile type 1 diabetes. Although the exact pathogenesis of LADA is unknown and questions the role of autoimmunity in beta cell failure, the familial aggregation of these two forms of diabetes underlines the existence of common roots, i.e. immune mechanisms and genetic susceptibility. This report clearly illustrates the differences in terms of autoimmunity (prevalence and titer of GAD and IA2 antibodies) and HLA class II genotype between patients with LADA and those with juvenile type 1 diabetes.