Persistent hypokalemia due to a rare mutation in gitelman's syndrome

Abstract

Chronic hypokalemia is the main finding in patients with Gitelman's syndrome (GS). GS, a variant of Bartter's syndrome, is an autosomal recessive renal disorder characterized by hypokalemia, hypomagnesemia, metabolic alkalosis, and hypocalciuria. GS is caused by inactivating mutations in the thiazide-sensitive sodium-chloride cotransporter gene. It is also called the "milder" form of Bartter's syndrome, as patients with GS are usually diagnosed in adulthood during routine investigation. Our objective is to highlight the impact of correct distinction between the causes of hypokalemia on management and the need of long-term follow- up after the restoration of normokalemic status. Herein, we report an asymptomatic 40-year-old male, whose persistent hypokalemia was due to GS. The diagnosis was first established by laboratory tests, and he was treated with low-dose aldosterone antagonists (spironolactone), angiotensin-converting enzyme inhibitors, and potassium and magnesium supplements. Genetic testing confirmed the diagnosis of GS and revealed a rare mutation. We conclude that GS is a rare and real diagnostic and therapeutic challenge, for which a close collaboration between endocrinologists and nephrologists is mandatory, as also the thorough genetic investigation of the mutations associated with this syndrome.