Table 1.

Causes of secondary FSGS.

Type	Cause
Adaptive (with reduced renal mass)	Oligomeganephronia, vesicoureteral reflux, low birth weight, unilateral renal agenesis, surgical renal ablation, chronic renal allograft nephropathy
Adaptive (with normal renal mass)	Systemic hypertension, obesity, increased lean body mass, renal vasoocclusive disease, cyanotic congenital heart disease, sickle cell anemia
Drug-induced	Heroin, pamidronate, interferon, lithium, sirolimus
Genetic	NPHS1, NPHS2, INF2, TRPC6, ACTN4, APOL1
Virus-associated	HIV-1, parvovirus B19, EBV, CMV