Alternative definition : NICHD: Segmental scarring of the glomerulus, which may result in isolated proteinuria
or nephrotic syndrome, which affects only part of the glomerulus and only some of
the glomeruli. Additionally, the Not Otherwise Specified classification excludes FSGS
tip, perihilar, collapsing, and cellular variants. (D'Agati VD, et al. Pathologic
Classification of Focal Segmental Glomerulosclerosis: A Working Proposal. Am J Kidney
Dis 43.2 (2004): 368-82.);