Abstract
Diabetes Mellitus is a group of complex diseases, characterized by the presence of hyperglycemia. Diabetes can be classified into several categories, type 1 DM, type 2 DM, Gestational Diabetes and other specific types of diabetes: within this category the monogenic diabetes is one of them and its pathophysiological affectation is due to the mutation of a single gene. Maternally inherited diabetes and deafness (MIDD) is a rare type of diabetes mellitus, caused by a mutation in mitochondrial DNA. It affects almost 1% of the population with diabetes but due to its clinical characteristics, it is commonly misdiagnosed by physicians as type 1 or type 2 DM the m.3243A> G mutation that corresponds to a substitution of an adenine molecule with a guanine molecule at position 3243 of the mitochondrial DNA.
A family history of diabetes, deafness and macular dystrophy is highly suggestive of the disease and the corresponding diagnostic tests must be performed. We present the case of a female patient diagnosed as type 1 DM at 23 years of age, with a history of bilateral sensorineural deafness, short stature, low BMI, receiving insulin therapy, admitted at the identification of macular dystrophy, detectable C Peptide levels, low IGF-1 and low growth hormone levels, negative Anti-GAD and Anti-Insulin antibodies, raised the possibility of Mitochondrial Diabetes and this diagnosis was further confirmed patient diagnosed and confirmed genetically with MIDD in Costa Rica.