ABSTRACT
Despite the abrupt clinical onset of type I Diabetes Mellitus [IDDM], the pathological autoimmune destruction of beta cell occurs in genetically susceptible individuals during an asymptomatic period: the prediabetic phase. Oral glucose tolerance test [OGTT] assay of islet cell autoantibodies [ICA] and insulin autoantibodies [IAA] were tested in 30 diabetic children and in 30 of their siblings; while determination of HLA-DQ Typing was done for the siblings of diabetic children. There were significant differences in frequencies of ICA[+] and IAA[+] in the siblings when compared with controls. Also there was negative correlation between the frequencies of ICA[+] and IAA[+] with the age in both groups. There was significant difference in the association of both autoantibodies in the sibling group, while it was absent in diabetic one. Certain susceptible DQ genotypes [DQw8 and DQw2] were detected in the siblings in significant difference when compared with controls. IDDM = Insulin Dependent Diabetes Mellitus; OGTT= Oral Glucose Tolerance Test; ICA= Islet Cell Autoantibodies; IAA= Insulin Autoantibodies; FBS= Fasting Blood Sugar