GLOMERULOESCLEROSE SEGMENTAR FOCAL (GESF) VARIANTE NOS EM PEDIATRIA: UM RELATO DE CASO

Focal segmental glomerulosclerosis (FSGS) is an important cause of proteinuria and nephrotic syndrome in childhood, presenting marked clinical, histopathological, and prognostic heterogeneity. Among its variants, the not otherwise specified (NOS) form is the most frequently diagnosed in pediatric patients and is often associated with atypical clinical presentations and a more indolent course. Early diagnosis and accurate etiological differentiation among primary, secondary, and genetic forms are essential for appropriate therapeutic management and for preventing progression of kidney disease. This study aimed to report and discuss a pediatric case of FSGS, NOS variant, emphasizing clinical, laboratory, histopathological, and therapeutic aspects, as well as prognostic implications. This is an observational case report based on the analysis of electronic medical records, approved by the Research Ethics Committee (approval no. 7,995,300). The male patient presented with persistent subnephrotic-range proteinuria, intermittent episodes of edema, and preserved renal function. Renal biopsy confirmed the diagnosis of FSGS, NOS variant, with findings suggestive of a secondary form. Therapeutic management was based on nephroprotective measures, including the use of an angiotensin-converting enzyme inhibitor, resulting in a progressive reduction of proteinuria and maintenance of renal function, without the need for immunosuppressive therapy. The favorable clinical evolution observed reinforces evidence from the literature associating proteinuria control with improved renal outcomes. In conclusion, this case highlights the importance of early diagnostic investigation, clinicopathological correlation, and long-term follow-up in children with FSGS, contributing to improved clinical management and prognosis in this population.