FOXO1-FGFR1 fusion and amplification in a solid variant of alveolar rhabdomyosarcoma

Mod Pathol. 2011 Oct;24(10):1327-35. doi: 10.1038/modpathol.2011.98. Epub 2011 Jun 10.

Abstract

Rhabdomyosarcoma is the most common pediatric soft tissue malignancy. Two major subtypes, alveolar rhabdomyosarcoma and embryonal rhabdomyosarcoma, constitute 20 and 60% of all cases, respectively. Approximately 80% of alveolar rhabdomyosarcoma carry two signature chromosomal translocations, t(2;13)(q35;q14) resulting in PAX3-FOXO1 fusion, and t(1;13)(p36;q14) resulting in PAX7-FOXO1 fusion. Whether the remaining cases are truly negative for gene fusion has been questioned. We are reporting the case of a 9-month-old girl with a metastatic neck mass diagnosed histologically as solid variant alveolar rhabdomyosarcoma. Chromosome analysis showed a t(8;13;9)(p11.2;q14;9q32) three-way translocation as the sole clonal aberration. Fluorescent in situ hybridization (FISH) demonstrated a rearrangement at the FOXO1 locus and an amplification of its centromeric region. Single-nucleotide polymorphism-based microarray analysis illustrated a co-amplification of the FOXO1 gene at 13q14 and the FGFR1 gene at 8p12p11.2, suggesting formation and amplification of a chimerical FOXO1-FGFR1 gene. This is the first report to identify a novel fusion partner FGFR1 for the known anchor gene FOXO1 in alveolar rhabdomyosarcoma.

Publication types

  • Case Reports

MeSH terms

  • Chromosomes, Human, Pair 13
  • Chromosomes, Human, Pair 8
  • Chromosomes, Human, Pair 9
  • Cytogenetic Analysis
  • Female
  • Forkhead Box Protein O1
  • Forkhead Transcription Factors / genetics*
  • Gene Amplification*
  • Gene Fusion*
  • Head and Neck Neoplasms / genetics*
  • Head and Neck Neoplasms / pathology
  • Humans
  • In Situ Hybridization, Fluorescence
  • Infant
  • Oligonucleotide Array Sequence Analysis
  • Polymorphism, Single Nucleotide
  • Receptor, Fibroblast Growth Factor, Type 1 / genetics*
  • Rhabdomyosarcoma, Alveolar / genetics*
  • Rhabdomyosarcoma, Alveolar / secondary
  • Translocation, Genetic

Substances

  • FOXO1 protein, human
  • Forkhead Box Protein O1
  • Forkhead Transcription Factors
  • FGFR1 protein, human
  • Receptor, Fibroblast Growth Factor, Type 1