Coenzyme Q10 supplementation in adult-onset focal segmental glomerulosclerosis caused by the Chinese common pathogenic variant c.737G &gt; A (p.Ser246Asn) in the <i>COQ8B</i> gene

COQ8B nephropathy, a mitochondrial disorder caused by mutations in the <i>COQ8B</i> gene, is a major pediatric genetic focal segmental glomerulosclerosis (GFSGS) etiology and stands out as one of the few treatable forms with good response to coenzyme Q10 (CoQ₁₀) supplementation. As the diagnosis and clinical experience of COQ8B nephropathy were predominantly in the pediatric population, the long-term efficacy of CoQ₁₀ supplementation and its application in the adult-onset patients remains largely unknown. Here, we report three cases of adult-onset FSGS from unrelated families, all carrying the Chinese common <i>COQ8B</i> mutation (c.737G &gt; A; p.Ser246Asn) with divergent trajectories of renal function following CoQ₁₀ supplementation initiated in different stages of renal dysfunction, providing valuable evidence on the implication of early disease diagnosis and prompt CoQ₁₀ supplementation for the prognosis of adult patients affected with COQ8B nephropathy.