P-278: Monogenic diabetes associated with hearing loss: report of two cases with SLC19A2 mutation and thiamine response
S S Velasquez Velasquez, L M Espinoza Colindres, K L Membreño LozanoAbstract
Introduction
The association of diabetes mellitus and hearing loss in pediatric age suggests rare monogenic etiologies, such as thiamine-sensitive megaloblastic anemia syndrome (TRMA) due to mutations in SLC19A2. It’s early recognition allows targeted management and modification of the clinical course.
Objectives
To describe two pediatric cases with diabetes and hearing loss in whom a mutation was confirmed in SLC19A2 and to evaluate their clinical evolution after treatment with thiamine
Methods
Clinical description and evolution of two clinical cases treated in the Endocrinology Service of the Hospital María, Pediatric Specialties
Results
Case 1: 7-year-old schoolboy with one year of polyuria, polydipsy and polyphagia, history of bilateral hearing loss with cochlear implant. He debuted with hyperglycemia (292 mg/dl), ketosis and HbA1c of 18.5%, initially managed with insulin. Genetic study confirmed homozygous mutation in SLC19A2. After initiation of thiamine (150 mg/day), metabolic control (HbA1c 6.4%) improved and insulin requirements were reduced. Case 2: 7-year-old female with anemia since breastfeeding and severe hearing loss. Incidental diagnosis of hyperglycemia (up to 314 mg/dl) without classic symptoms. HbA1.c: 10.1%, low C peptide. Hemoglobin: 10.6 g/dl, Mean corpuscular volume: 88.9 fl, mean corpuscular hemoglobin concentration: 33.9 g/dl. Genetic confirmation of homozygous mutation in SLC19A2. He started insulin and later thiamine, with clinical and metabolic improvement.
Conclusions
The coexistence of diabetes, hearing loss and hematological history should alert on TRMA. Genetic diagnosis is essential, since treatment with thiamine improves glycemic control and reduces insulin dependence. These cases highlight the importance of suspecting monogenic diabetes in atypical presentations.