A Rare Case of Bartter Syndrome Type 3 Presenting With New-Onset Diabetes Mellitus.

Bartter syndrome is a rare genetic disorder that often presents in the early phase of life and is caused by mutations in multiple genes encoding the transporters and channels, which are responsible for the reabsorption of various ions in the nephrons. Clinically, it presents with vomiting, failure to thrive, and dehydration. Rare instances of acquired Bartter syndrome have been linked to sarcoidosis, tuberculosis, and autoimmune diseases. Here, we discuss the case of a 52-year-old male patient who presented with complaints of multiple episodes of vomiting and mental obtundation. On further evaluation, he was found to have salt-losing tubulopathy, hypokalemia, and metabolic alkalosis. In the absence of genetic studies, the diagnosis of Bartter syndrome poses a diagnostic challenge in clinical practice.