Description : Nephrotic syndrome type 9 (NPHS9) is an autosomal recessive chronic kidney disorder
characterized by significant proteinuria resulting in hypoalbuminemia and edema. Onset
is in the first or second decade of life. The disorder is steroid treatment-resistant
and usually progresses to end-stage renal disease requiring transplantation. Renal
biopsy shows focal segmental glomerulosclerosis (FSGS) or collapsing FSGS (summary
by Ashraf et al., 2013). For a general phenotypic description and a discussion of
genetic heterogeneity of nephrotic syndrome and FSGS, see NPHS1 (256300).;
Inheritance : Autosomal recessive;
Molecular basis : Caused by mutation in the AARF domain-containing kinase 4 gene (ADCK4, 615567.0001);
Laboratory abnormalities : Defective mitochondrial respiratory enzyme activity; Hypoalbuminemia; Proteinuria; Decreased CoQ10 levels in lymphoblasts or fibroblasts;