Case Report: A Multisystem Mystery: Unraveling HNF1β-Associated Glomerulocystic Disease in a 30-year-old Female

The hepatocyte nuclear factor 1 beta (HNF1β) gene codes for a transcription factor involved in embryonic development and mitochondrial function, primarily in the kidney, liver, pancreas, and reproductive system. HNF1β-associated glomerular cystic kidney disease is a rare hereditary condition characterized by electrolyte disturbances, renal abnormalities, and multisystem involvement, commonly presenting as Renal Cysts and Diabetes (RCAD), often accompanied by maturity-onset diabetes of the young (MODY). We report a case of a 30-year-old female with no significant medical history who presented with severe abdominal pain radiating to her back, nausea, and vomiting. Initial evaluation revealed hypomagnesemia, hypokalemia, elevated liver function tests, renal and hepatic cysts, and a congenital bicornuate uterus. Genetic testing confirmed the diagnosis, identifying an HNF1β mutation due to a 17q12 deletion. She received symptomatic treatment, including pain management, electrolyte replacement, and supportive care. Attempts with amiloride and oral magnesium supplementation failed to maintain therapeutic magnesium levels, resulting in recurrent hospitalizations. Consequently, the patient required ongoing outpatient intravenous magnesium infusions (4 grams thrice weekly), effectively preventing further admissions. She also receives Vitamin D supplementation. Despite the typical disease association with MODY, she has no evidence of diabetes mellitus. This case highlights the complexity of HNF1β-associated glomerulocystic kidney disease, underscoring the importance of genetic testing for accurate diagnosis and treatment. It also emphasizes the necessity of a multidisciplinary management strategy to address this rare condition's diverse clinical manifestations and prevent recurrent complications.