title: The podocin mutation R229Q and early recurrence (within the first year) of glomerular disease after renal transplantation.
abstract: BACKGROUND
  Podocin is a key protein involved in the pathogenesis of steroid-resistant nephrotic syndrome and/or focal segmental glomerulosclerosis (FSGS) and is characterized by a high rate of early recurrence after renal transplantation (RTx) in children and adults.
  
  
  METHODS
  We studied 206 RTx adult recipients: 187 with a diagnosis of glomerular nephropathy, GN (biopsy-proven in 149, clinical in 38), plus 19 with unknown diagnosis as original kidney disease (OKD), the NPHS2 gene polymorphism, G755A, and correlated with the presence of early recurrence of OKD within the first year (proteinuria over 1 g/day and graft-biopsy proven).
  
  
  RESULTS
  The A allele podocin gene mutation frequency was 3.4% (14/412) overall - 7.1% (4/56) in FSGS as expected, but surprisingly 5.7% (6/106) in IgA nephropathy. Fifty recipients (24.3%) developed proteinuria >1 g/d, with 12 recipients demonstrating early clinico-pathological recurrence by 1 year (5.8%) with 5/28 in FSGS, 2/53 in IgAN, 2/14 in membranoproliferative GN (with 1 graft loss within the first year), 1/19 in crescentic GN, 1/19 in unknown disease, and 1/38 in clinical GN. Only 2 recurrent patients (both with FSGS) had the R229Q podocin mutation (16.7%).
  
  
  CONCLUSIONS
  The podocin mutation R229Q may play a role in the pathogenesis of FSGS and in early recurrence after transplantation, but does not allow accurate prediction of recurrence or the associated potential for prevention.
authors: Department of Nephrology, Dialysis and Renal Transplantation, University Hospital of Saint-Etienne, Saint-Etienne, France.
authors: Hesham
authors: H
authors: Mohey
authors: Lise
authors: L
authors: Thibaudin
authors: Blandine
authors: B
authors: Laurent
authors: Francois
authors: F
authors: Berthoux
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D005921:Glomerulonephritis / Q000235:genetics / Q000601:surgery; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D007674:Kidney Diseases / Q000235:genetics* / Q000601:surgery; D016030:Kidney Transplantation; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D009404:Nephrotic Syndrome / Q000235:genetics / Q000601:surgery; D011110:Polymorphism, Genetic; D011507:Proteinuria / Q000235:genetics / Q000601:surgery; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C407223:NPHS2 protein