An interesting unfolding of the diagnosis of hepatocyte nuclear factor ‐1 beta (HNF1β) monogenic diabetes

We present a case of RCAD syndrome with a previously unreported mutation. A 49‐year‐old man with diabetes mellitus was admitted with worsening chronic kidney disease requiring haemodialysis. He developed recurrent, unexplained hypoglycaemia despite discontinuing insulin, making the diagnosis of type 1 diabetes mellitus questionable. He had detectable serum C‐peptide (742 pmol/L), and anti‐GAD and anti‐pancreatic islet cell antibodies were negative. Abdominal imaging revealed renal cortical cysts and atrophic pancreas. A significant family history of diabetes mellitus with renal disease was also established which prompted us to suspect mutation of the HNF1B gene. Genetic testing confirmed the diagnosis: he was found to have a novel HNF1B missense mutation p.R165C previously not reported. This case study identified a mutation previously unreported thereby expanding the spectrum of HNF1B gene mutations. Copyright © 2017 John Wiley & Sons.
Source: Practical Diabetes - Category: Endocrinology Authors: Tags: Case report Source Type: research