A Case of Diabetes Mellitus Associated with the Mitochondrial ND1 T3308C Mutation and Morphological Abnormalities of Mitochondria in Cardiomyocytes

Abstract

37-year-old male with obesity developed type 2 diabetes mellitus and hypertension at 25 years of age, heart and renal failures at 31 years of age and peripheral artery disease at 36 years of age. Anamnesis disclosed an older brother with hypertension and obesity, a maternal aunt with diabetes and obesity and a maternal grandaunt with diabetes. The patient was admitted to our hospital for the evaluation and treatment of diabetes and obesity. A laboratory examination disclosed a low insulin secretory capacity (serum C-peptide: 0.21 ng/ml) in addition to the presence of advanced chronic diabetic complications and atherosclerosis. Echocardiography revealed diffuse left ventricular hypertrophy and left atrial/ventricular dilatation, while an electron microscopic image of a myocardial biopsy specimen demonstrated morphological mitochondrial abnormalities in cardiomyocytes. A mitochondrial DNA analysis of peripheral blood cells showed the T3308C homoplastic mutation in the NADH dehydrogenase subunit 1 gene. This is the first report of the T3308C mutation in the Japanese population. This mutation appears to be associated with the development of diabetes mellitus, hypertension and cardiomyopathy.