Figure 1 Schematic representation of idiopathic nephrotic syndrome, minimal change disease and idiopathic focal segmental glomerulosclerosis (FSGS) Figure 1 | Schematic representation of idiopathic nephrotic syndrome, minimal change disease and idiopathic focal segmental glomerulosclerosis (FSGS). Idiopathic nephrotic syndrome is caused by unknown initiating events (A, B and C) that lead to podocyte damage. Clinical features include gross proteinuria and hypoalbuminaemia, often accompanied by oedema and dyslipidaemia. The disease is histologically defined by complete podocyte foot process effacement with no immune deposits and no glomerular basement alterations. On light microscopy, either normal appearing glomeruli or FSGS might be visible. Disease outcomes are unpredictable at diagnosis, and might include steroid-induced proteinuria remission, potentially followed by relapse, or (primary or secondary) corticosteroid resistance. Patients with persistent proteinuria ultimately develop FSGS. Minimal change disease and idiopathic FSGS are manifestations of idiopathic nephrotic syndrome that are defined by histology and/or clinical outcomes; minimal change disease is characterized by foot process effacement, normal glomeruli and steroid sensitivity, whereas idiopathic FSGS is characterized by foot process effacement and FSGS lesions. Maas, R. J. et al. (2016) Minimal change disease and idiopathic FSGS: manifestations of the same disease Nat. Rev. Nephrol. doi:10.1038/nrneph.2016.147