Hyponatremia - A rare complication of Gitelman's syndrome

Abstract

Gitelman's syndrome (GS) is a rare autosomal recessive disorder caused by mutations in thiazide-sensitive NaCl cotransporter. We report a 49-year-old, normotensive lady with prolonged hypokalemia since her 20s who was diagnosed with GS at our renal clinic. During follow-up, she was found to have mild, asymptomatic, euvolemic hyponatremia with low serum uric acid, inappropriately high urine osmolality and sodium consistent with syndrome of inappropriate antidiuretic hormone-like presentation. Despite life-long urinary sodium losses, hyponatremia has rarely been reported in GS to be due to the primary disease process. We present relevant clinical data and hypothesize on why this disease per se may be a risk factor for dilutional hyponatremia.

Hypocalcaemia and hyponatraemia masquerading the diagnosis of Gitelman syndrome

“…An extensive review of literature revealed only three cases reported until now, being first reported by Schepkens et al 21 in two patients in 2001. In light of these cases, the presence of hyponatraemia may be attributed to the multifaceted, intricate interplay between life-long tubular salt wasting, antidiuretic hormone hyper-secretion owing to extracellular volume depletion, and diminished diluting function of the distal tubules 22. When present, it induces symptoms such as headache, nausea and mental confusion.…”