RESUMEN
OBJECTIVE: Maturity-onset diabetes of the young (MODY) type 5 is caused by an autosomal dominant mutation in the HNF1B gene. Our objective was to report a case of a young girl with bicornuate uterus and recurrent renal stones with diabetes mellitus (DM) without a family history that was diagnosed to be MODY 5. CASE REPORT: A 12-year-old girl presented with recurrent renal stones that were managed with lithotripsy and double-J stenting at various time points. At the age of 14 years, she was found to have a bicornuate uterus with an absent cervix and vagina. She was diagnosed with DM at the age of 16 years without a preceding history of osmotic symptoms or steatorrhea. Although there was no family history of young-onset diabetes, given her long-standing history of müllerian abnormalities, renal cysts, and pancreatic hypotrophy, she was evaluated for MODY. Using the next-generation sequencing, she was found to be positive for a reported HNF1B gene pathogenic mutation c.494G>A (p.Arg165His), confirming a diagnosis of MODY 5. DISCUSSION: There is a significant overlap in clinical criteria for type 2 DM and MODY in the Asian Indian population. The HNF1B gene mutation is difficult to diagnose as none of the clinical manifestations are pathognomonic and many lack a family history of DM. Diagnostic algorithms with specific clinical and biochemical criteria along with pancreatic imaging can help in case detection and direct toward particular genetic mutation analysis. CONCLUSION: We suggest that genetic testing be offered to patients with otherwise unexplained DM and such genitourinary anomalies.