Abstract
Focal segmental glomerulosclerosis (FSGS) is one of the leading causes of primary end-stage kidney disease in the pediatric age group. It is commonly associated with steroid-resistant nephrotic syndrome (SRNS), which ultimately leads to impairment in the function of the glomerular filtration system. Genetic studies have revealed nearly 50 types of gene deficiency disorders linked to the development of both FSGS and SRNS. Among these disorders, primary coenzyme Q10 (CoQ10) deficiency is classified as one of the few types that respond well to treatment. CoQ10 plays a crucial role within the mitochondria, including energy production through the electron transport chain. A network of at least 17 genes is necessary for its synthesis. When mutations occur in the genes responsible for CoQ10 production, a deficiency can develop, leading to mitochondrial dysfunction and reduced cellular energy levels. Since CoQ10 is crucial for mitochondrial function, its deficiency has been recognized as a potential therapeutic target. Increasing evidence suggests that CoQ10 supplementation may provide clinical benefit in treating this condition. We present three pediatric cases of SRNS that did not respond to standard treatment. Despite kidney biopsies revealing FSGS, conventional therapies proved ineffective. The patients were started on CoQ10 supplementation, which led to a complete resolution of nephrotic syndrome. Their kidney function remained within the normal range during follow-up, and proteinuria remained stable, indicating a sustained therapeutic response.