title: Bilateral Wilms tumor and early presentation in pediatric patients is associated with the truncation of the Wilms tumor 1 protein.
abstract: OBJECTIVE
  To investigate the frequency of constitutional Wilms tumor 1 gene (WT1) abnormalities in children with bilateral Wilms tumor (WT) and the age of tumor onset in patients with a mutation.
  
  
  METHODS
  Eight patients with bilateral WT were studied. High-resolution melting and direct sequencing were used to screen for the WT1 gene. Western blotting was performed to determine whether the identified mutations were associated with expressed truncated WT1 protein.
  
  
  RESULTS
  The median age of tumor onset in patients with a mutation in the WT1 was lower (10 months) than in those without a mutation (39 months). Three novel heterozygous nonsense mutations were identified in exon 8 in peripheral blood from 3 individuals, whereas all 3 tumor tissues lacked the wild-type allele. All mutations led to a premature stop codon with truncation of the WT1 protein. In 1 patient, a truncated form of WT1 protein was identified, suggesting that development of the WT may have resulted from expression of an abnormal protein. Four distinct silent single-nucleotide polymorphisms (SNPs) were detected. All 3 patients with a pathogenic WT1 mutation had 2 synonymous SNPs, whereas only 1 of the remaining 5 patients had a single synonymous SNP (P < .05).
  
  
  CONCLUSIONS
  Bilateral WT are associated with early presentation in pediatric patients and a high frequency of WT1 nonsense mutations in exon 8. Silent SNPs may also be involved in the development of WT.
authors: Center for Kidney Research, Children's Hospital at Westmead, The University of Sydney, Westmead, NSW, Australia.
authors: Min
authors: M
authors: Hu
authors: Jeffery
authors: J
authors: Fletcher
authors: Emma
authors: E
authors: McCahon
authors: Daniel
authors: D
authors: Catchpoole
authors: Geoff Y
authors: GY
authors: Zhang
authors: Yuan Min
authors: YM
authors: Wang
authors: Elizabeth M
authors: EM
authors: Algar
authors: Stephen I
authors: SI
authors: Alexander
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D016162:Genes, Wilms Tumor; D006801:Humans; D007223:Infant; D007680:Kidney Neoplasms / Q000235:genetics*; D008297:Male; D009154:Mutation; D025721:WT1 Proteins / Q000235:genetics*; D009396:Wilms Tumor / Q000235:genetics*
chemical_list: D025721:WT1 Proteins