The nephrotic syndrome is characterized clinically by proteinuria, hypoalbuminemia, hyperlipidemia, and edema. Kidney biopsies show nonspecific histologic changes such as minimal change, focal segmental glomerulosclerosis (FSGS), and diffuse mesangial proliferation. Approximately 20% of affected individuals have an inherited steroid-resistant form and progress to end-stage renal failure (summary by Fuchshuber et al., 1996). Nephrotic syndrome type 1 (NPHS1) is characterized by prenatal onset of massive proteinuria followed by severe steroid-resistant nephrotic syndrome apparent at birth with rapid progression to end-stage renal failure (Kestila et al., 1998). Because of confusion in the literature regarding use of the terms 'nephrotic syndrome' and 'focal segmental glomerulosclerosis' (see NOMENCLATURE section), these disorders in OMIM are classified as NPHS or FSGS according to how they were first designated in the literature. Genetic Heterogeneity of Nephrotic Syndrome and Focal Segmental Glomerulosclerosis Nephrotic syndrome and FSGS are genetically heterogeneous disorders representing a spectrum of hereditary renal diseases. See also NPHS2 (600995), caused by mutation in the podocin gene (604766); NPHS3 (610725), caused by mutation in the PLCE1 gene (608414); NPHS4 (256370), caused by mutation in the WT1 gene (607102); NPHS5 (614199), caused by mutation in the LAMB2 gene (150325); NPHS6 (614196), caused by mutation in the PTPRO gene (600579); NPHS7 (615008), caused by mutation in the DGKE gene (601440); NPHS8 (615244), caused by mutation in the ARHGDIA gene (601925); NPHS9 (615573), caused by mutation in the COQ8B gene (615567); NPHS10 (615861), caused by mutation in the EMP2 gene (602334); NPHS11 (616730), caused by mutation in the NUP107 gene (607617); NPHS12 (616892), caused by mutation in the NUP93 gene (614351); NPHS13 (616893), caused by mutation in the NUP205 gene (614352); NPHS14 (617575), caused by mutation in the SGPL1 gene (603729); NPHS15 (617609), caused by mutation in the MAGI2 gene (606382); NPHS16 (617783), caused by mutation in the KANK2 gene (614610), NPHS17 (618176), caused by mutation in the NUP85 gene (170285); NPHS18 (618177), caused by mutation in the NUP133 gene (607613); NPHS19 (618178), caused by mutation in the NUP160 gene (607614); NPHS20 (301028), caused by mutation in the TBC1D8B gene (301027); NPHS21 (618594) caused by mutation in the AVIL gene (613397); NPHS22 (619155), caused by mutation in the NOS1AP gene (605551); NPHS23 (619201), caused by mutation in the KIRREL1 gene (607428); NPHS24 (619263), caused by mutation in the DAAM2 gene (606627); and NPHS26 (620049), caused by mutation in the LAMA5 gene (601033). The symbol NPHS25 has been used as an alternative designation for NPHS21. See also FSGS1 (603278), caused by mutation in the ACTN4 gene (604638); FSGS2 (603965), caused by mutation in the TRPC6 gene (603652); FSGS3 (607832), associated with variation in the CD2AP gene (604241); FSGS4 (612551), mapped to chromosome 22q12; FSGS5 (613237), caused by mutation in the INF2 gene (610982); FSGS6 (614131), caused by mutation in the MYO1E gene (601479); FSGS7 (616002), caused by mutation in the PAX2 gene (167409); FSGS8 (616032), caused by mutation in the ANLN gene (616027); and FSGS9 (616220), caused by mutation in the CRB2 gene (609720).

Galloway-Mowat syndrome is a renal-neurologic disease characterized by early-onset nephrotic syndrome associated with microcephaly, gyral abnormalities, and delayed psychomotor development. Most patients have dysmorphic facial features, often including hypertelorism, ear abnormalities, and micrognathia. Other features, such as arachnodactyly and visual impairment, are more variable. Most patients die in the first years of life (summary by Braun et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of GAMOS, see GAMOS1 (251300).