SLC19A2 and diabetes mellitus: We present the case of a woman diagnosed with thiamine-responsive megaloblastic anemia, with no history of consanguinity, in whom genetic testing revealed novel SLC19A2 mutations and an unreported clinical manifestation.<h4>Case presentation</h4>This case describes an 18-year-old mestizo female patient who presented with a medical history of diabetes starting in infancy, bilateral sensorineural hearing loss, and megaloblastic anemia.