A case of Gitelman syndrome with severe hyponatraemia and hypophosphataemia

Abstract

Gitelman syndrome (GS) is a renal tubular disorder of the thiazide-sensitive sodium chloride cotransporter, which is located in the distal tubule of the loop of Henle. We present a rare case of GS complicated by severe hyponatraemia and hypophosphataemia. A 17-year-old boy was admitted to our institution with fever and lethargy. The workup revealed typical features of GS, i.e. hypokalaemia, hypomagnesaemia and metabolic alkalosis. In this report, we discuss the differential diagnoses and rationale for accepting GS as the most likely diagnosis. This case was complicated by severe hyponatraemia (115 mmol/L) and hypophosphataemia (0.32 mmol/L). We concluded that the syndrome of inappropriate secretion of antidiuretic hormones could not be ruled out and that respiratory alkalosis was the most likely aetiology of hypophosphataemia. This case report also generates an interesting discussion on water and electrolyte metabolism.

Hyponatremia - A rare complication of Gitelman's syndrome

“…An extensive literature search revealed only 3 cases of GS reported with coincidental hyponatremia. [23] Schepkens et al . reported 2 cases both with a long-standing diagnosis of GS preceding hyponatremia.…”

“…reported euvolemic hyponatremia in a 17-year-old boy hospitalized for pneumonia who also had normal blood pressure, hypokalemia, hypomagnesemia, and metabolic alkalosis. [3] A de novo diagnosis of GS was made in the acute setting. The cause of hyponatremia was attributed to SIADH although no hypouricemia was documented and follow-up clinical data specifically related to serum sodium and treatment of hyponatremia was lacking.…”

“…The cause of hyponatremia was attributed to SIADH although no hypouricemia was documented and follow-up clinical data specifically related to serum sodium and treatment of hyponatremia was lacking. [3]…”

“…[2]) and pneumonia induced ADH hypersecretion (the case of Ali et al . [3]) is sufficient to trigger clinical hyponatremia. The closest differential diagnosis in our patient was reset osmostat syndrome which is usually mild (unlike our case) and does not normalize with free water restriction.…”

“…[2] Despite lifelong phenomena of renal salt wasting, reports of hyponatremia in this disease is rare and coincident to other commonly attributable causes. [23]…”