Unusual association of Gitelman syndrome with early diagnosis and glomerular proteinuria; a case report

Abstract

Gitelman syndrome is an autosomal recessive hereditary tubulopathy whose main alteration is at the sodium-chloride symporter in the distal convoluted tubule, characterized by metabolic alkalosis, normotension, hypokalemia, hypomagnesemia and hypocalciuria. Proteinuria and glomerular hyperfiltration (especially at the beginning of clinical course) are not characteristic manifestations of this disease. We present the case of a 25-year-old female with recent diagnosis of Gitelman syndrome who presented with hyperfiltration and glomerular proteinuria, leading to a renal biopsy, which showed hypertrophy of juxtaglomerular apparatus and mesangial proliferation. In electron microscopy focal podocyte detachment was evidenced, which was compatible with secondary focal segmental glomerulosclerosis (FSGS). This case of association of tubulopathy with secondary glomerulopathy of early presentation, shows the final pathway in this disease, when generating sustained renal ischemia due to the increased activity of renin-angiotensin-aldosterone system (RAAS). Renal biopsy and electron microscopy proved to be useful to define prognosis, early recognition of progression and adjust treatment in this patient.

Keywords: Gitelman syndrome, Hypokalemia, Juxtaglomerular apparatus hypertrophy, Focal segmental glomerulosclerosis, Hyperfiltration, Proteinuria