A young female with Spitzer-Weinstein syndrome diagnosed by thiazide test

Spitzer-Weinstein syndrome is a rare disorder characterized by thiazide responsive hyperkalemia and normal anion gap metabolic acidosis, similar to Gordon syndrome. The hyperfunction of thiazide-sensitive Na+-Cl- cotransporter (TSC) is the main pathophysiological mechanism. We presented a 19-year-old female with short stature, normal blood pressure, persistently elevated serum potassium, and metabolic acidosis. The diagnosis of Spitzer-Weinstein Syndrome was made by clinical pictures and thiazide test. After taking 4 mg hydrochlorothiazide, her daily urine potassium excretion increased from 18.1 mmol to 41.8 mmol, urine pH decreased from 7.32 to 6.50, and urinary net charge decreased from 65.7 to 54.4. This patient then took hydrochlorothiazide 4 mg daily. The persistent hyperkalemia and metabolic acidosis were corrected. Thiazide, a powerful inhibitor of TSC, proved to be a useful tool for the diagnosis and treatment of Spitzer-Weinstein syndrome.