Acute quadriparesis revealing Gitelman syndrome: a case report

Gitelman syndrome (GS) is a rare autosomal recessive renal tubulopathy caused by SLC12A3 gene mutations, leading to hypokalemia, metabolic alkalosis, hypomagnesemia, and hypocalciuria. Its estimated prevalence ranges from 1 to 10 per 40 000 individuals worldwide, with a carrier frequency approaching 1%, underscoring its potential public health relevance despite underdiagnosis. This case highlights a rare presentation of GS with acute quadriparesis mimicking neurological emergencies, emphasizing the risk of misdiagnosis in acute care settings.

A 30-year-old female presented with acute-onset fever, vomiting, and progressive quadriparesis. Examination revealed flaccid paralysis (power: 2/5), areflexia, and bulbar weakness. Critical biochemical findings included severe hypokalemia (K⁺: 1.6 mmol/l), hypomagnesemia (1.19 mg/dl), metabolic alkalosis (pH: 7.48, HCO₃ ^-: 32 mEq/l), hypocalciuria (6.43 mg/24 h), low urinary potassium, and elevated serum renin.

This case demonstrates an intercurrent illness that precipitated acute decompensation in previously undiagnosed GS, leading to profound weakness mimicking Guillain-Barré syndrome, periodic paralysis and Bartter syndrome. The key to diagnosis lies in recognizing the distinctive biochemical triad of hypokalemia, hypomagnesemia, and hypocalciuria with renal potassium wasting. Although genetic testing for SLC12A3 mutations remains the diagnostic gold standard, it is often unavailable in resource-limited settings, making biochemical recognition crucial.

GS is a great mimicker that can present with acute severe paralysis. Clinicians must include it in the differential for unexplained hypokalemia and metabolic alkalosis, as prompt recognition and management with magnesium and potassium supplementation are crucial to prevent life-threatening arrhythmias, recurrent paralysis and reduce long-term morbidity.