Mitochondrial disease: An uncommon but important cause of diabetes mellitus

Mitochondrial diseases are rare, heterogeneous conditions affecting organs dependent on high aerobic metabolism. Presenting symptoms and signs vary depending on the mutation and mutant protein load. Diabetes mellitus is the most common endocrinopathy, and recognition of these patients is important due to its impact on management and screening of family members. In particular, glycemic management differs in these patients: the use of metformin is avoided because of the risk of lactic acidosis. We describe a patient who presented with gradual weight loss and an acute presentation of hyperglycemia complicated by the superior mesenteric artery syndrome. His maternal history of diabetes and deafness and a personal history of hearing impairment led to the diagnosis of a mitochondrial disorder.