Mutational analysis of NPHS2 and WT1 in frequently relapsing and steroid-dependent nephrotic syndrome

Pediatr Nephrol. 2007 Apr;22(4):509-13. doi: 10.1007/s00467-006-0377-y. Epub 2007 Jan 10.


Idiopathic nephrotic syndrome is a common pediatric kidney disease, 80% of all cases are steroid sensitive (SSNS). A significant proportion of children with SSNS will have a frequently relapsing or steroid-dependent course (FRNS/SDNS) that is associated with significant treatment-related morbidity. Mutations in NPHS2 account for more than 28% of all cases of steroid-resistant nephrotic syndrome (SRNS) and dominant mutations in WT1 for 5%; while mutations are absent from children with uncomplicated SSNS. Since FRNS/SDNS is phenotypically positioned within a spectrum between SSNS and SRNS, we hypothesized that heterozygous mutations of NPHS2 may be causing FRNS/SDNS. Mutational analysis of NPHS2 and WT1 was carried out in a single-center cohort of 20 children with FRNS/SDNS, ten children with uncomplicated SSNS (control), and 22 children with SRNS (control). Renal biopsy findings were available in 15/20 children with FRNS/SDNS and revealed IgM nephropathy, MCNS, and FSGS in six, five, and four children, respectively. Children with FRNS/SDNS were significantly younger at first presentation than those with SSNS and SRNS (median age: 3.0 years in FRNS/SDNS patients, 7.0 years in SSNS patients, and 5.0 in SRNS patients; p < 0.001). No NPHS2 or WT1 mutations were found in patients with FRNS/SDNS and uncomplicated SSNS. The hypothesis that FRNS/SDNS may be associated with heterozygous mutations in NPHS2 or WT1 was not confirmed.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • DNA Mutational Analysis
  • Female
  • Heterozygote
  • Homozygote
  • Humans
  • Infant
  • Intracellular Signaling Peptides and Proteins / genetics*
  • Male
  • Membrane Proteins / genetics*
  • Mutation / genetics*
  • Nephrotic Syndrome / genetics*
  • Polymerase Chain Reaction
  • Recurrence
  • Steroids*
  • WT1 Proteins / genetics*


  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • NPHS2 protein
  • Steroids
  • WT1 Proteins