Abstract: SA-PO0156
A Hidden Salt-Wasting Tubulopathy in a Young Man with Recurrent Electrolyte Abnormalities
Session Information
- Tubular, Metabolic, and Systemic Noncystic Genetic Kidney Diseases
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Genetic Diseases of the Kidneys
- 1202 Genetic Diseases of the Kidneys: Non-Cystic (Complex and Non-Cystic Monogenic)
Authors
- Bapar, Abdul Haseeb, Richmond University Medical Center, New York, New York, United States
- Ogunniyi, Kayode E., Richmond University Medical Center, New York, New York, United States
- Dalezman, Solomon, Richmond University Medical Center, New York, New York, United States
Introduction
Gitelman syndrome (GS) is an autosomal recessive salt-wasting tubulopathy caused by mutations in the SLC12A3 gene, which encodes the thiazide-sensitive sodium-chloride cotransporter. It is characterized by hypokalemic metabolic alkalosis, hypomagnesemia, and hypocalciuria.
Case Description
A 32-year-old man with epilepsy on levetiracetam presented after a fall associated with transient loss of consciousness. He denied vomiting, diarrhea, recent illness, diuretic or laxative use, alcohol, tobacco, or illicit drug use. There was no family history of kidney disease. Blood pressure was 98/64 mmHg, and examination was unremarkable.
Initial laboratory evaluation revealed potassium 2.6 mmol/L, magnesium 1.15 mg/dL, bicarbonate 32 mmol/L, sodium 136 mmol/L, calcium 9.3 mg/dL, and creatinine 1.3 mg/dL. Despite copious electrolyte supplementation, hypokalemia and hypomagnesemia persisted. Urine studies demonstrated renal potassium, chloride and magnesium wasting with urine potassium 78 mmol/L, urine chloride 129mmol/L and urine magnesium 10.65 mg/dL. Fractional excretion of potassium and magnesium were markedly elevated. The twenty-four-hour urine calcium/creatinine ratio was 112 mg/g, consistent with hypocalciuria. Renal imaging showed no hydronephrosis or nephrocalcinosis. Aldosterone-to-renin ratio was normal at 2.2.
Discussion
The combination of persistent hypokalemia, hypomagnesemia, metabolic alkalosis, renal electrolyte wasting, hypocalciuria, normotension, and absence of gastrointestinal losses or diuretic exposure was highly suggestive of Gitelman syndrome. This case highlights the importance of considering inherited salt-wasting tubulopathies in young adults with unexplained electrolyte abnormalities. Differentiation from acquired causes of hypokalemia is important because GS typically presents later in life with hypomagnesemia, hypocalciuria, and normotension. Long-term management includes potassium and magnesium supplementation with monitoring for recurrent electrolyte abnormalities and arrhythmic complications, particularly in patients with seizure disorders in whom electrolyte derangements may lower seizure threshold. GS should be suspected in patients with persistent hypokalemia, hypomagnesemia, metabolic alkalosis, renal electrolyte wasting, and hypocalciuria. Careful biochemical evaluation can support the diagnosis.
Acknowledgment
Portions of this abstract were prepared with assistance from generative AI software for editing and language improvement; all scientific content, interpretation, and final review were performed by the authors.