A case of Gitelman syndrome with membranous nephropathy
A male patient had a 4-year history of recurrent fatigue. Serum biochemistry revealed hypokalemia with renal potassium wasting, hypomagnesemia, metabolic alkalosis, hyperreninemia, hypocalciuria, as well as nephrotic-range proteinuria, hypoalbuminemia, and elevated serum anti-phospholipase A2 receptor (PLA2R) antibody. Gene sequencing identified compound heterozygous mutations in SLC12A3 [c.536T>A(p.V179D) and c.1456G>A(p.D486N)]. The unusual association of SLTs and nephrotic-range glomerular proteinuria prompted us to perform a renal biopsy. Renal biopsy showed idiopathic MN. Due to the potential to activate the sodium-chloride co-transporter (NCC) and cause hyperkalemia, tacrolimus was selected to treat NS. Following treatment with potassium chloride, magnesium oxide, and low-dose glucocorticoid combined with tacrolimus, the fatigue significantly improved, and concurrently hypokalemia, and hypomagnesemia were corrected and NS was remitted.

Source: https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-022-02875-8