title: Retinoblastoma associated with chromosomal 13q14 deletion mosaicism.
abstract: OBJECTIVE
  To assess the risk of retinoblastoma developing in children with microscopic chromosomal with mosaic deletions involving 13q14.
  
  
  METHODS
  Case report and systematic literature review.
  
  
  METHODS
  Data on 29 patients with a mosaic and 107 patients with a nonmosaic somatic deletion of chromosome 13q14 were compared.
  
  
  METHODS
  Age at diagnosis, frequency, and laterality of retinoblastoma.
  
  
  METHODS
  A dysmorphic baby, who carried a chromosomal deletion involving 13q14 in 34% of peripheral blood lymphocytes, had neuroradiologic evidence of retinoblastoma at the age of 2 weeks. She developed trilateral retinoblastoma, a pineal neuroblastic tumor, at the age of 10 months. The diagnosis of her tumor was delayed because of misjudgment of risk of retinoblastoma developing.
  
  
  RESULTS
  Meta-analysis revealed no difference between children with mosaic and nonmosaic chromosomal deletion of 13q14 regarding the age at diagnosis, laterality of tumor, and presence of family history for retinoblastoma. A lower percentage of somatic cells with mosaic deletion did not predict a higher age at diagnosis or unilateral tumors. No statistically significant difference was noted regarding the presence of mental retardation, dysmorphic features, and anomalies of internal organs between mosaic and nonmosaic deletions. Only 7% (95% confidence interval, 1-23) of 29 patients who had a mosaic chromosomal deletion including 13q14 were not reported to develop retinoblastoma.
  
  
  CONCLUSIONS
  Whenever a 13q14 deletion is diagnosed, immediate ophthalmologic evaluation is recommended to ensure prompt diagnosis of retinoblastoma. Mosaic and nonmosaic chromosomal deletions of 13q14 do not differ regarding the risk and type of retinoblastoma developing.
authors.affiliation: Pediatric Ophthalmology and Oncology Service, Department of Ophthalmology, Helsinki University Central Hospital, Haartmaninkatu 4 C, PL 220, FIN-00029 HUS, Helsinki, Finland.
authors.forename: Tero
authors.initials: T
authors.lastname: Kivelä
authors.forename: Kaija
authors.initials: K
authors.lastname: Tuppurainen
authors.forename: Pekka
authors.initials: P
authors.lastname: Riikonen
authors.forename: Matti
authors.initials: M
authors.lastname: Vapalahti
mesh_terms: D001932:Brain Neoplasms / Q000175:diagnosis / Q000235:genetics; D002872:Chromosome Deletion; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D009030:Mosaicism / Q000235:genetics*; D010870:Pineal Gland / Q000473:pathology; D010871:Pinealoma / Q000175:diagnosis / Q000235:genetics; D019572:Retinal Neoplasms / Q000175:diagnosis / Q000235:genetics*; D012175:Retinoblastoma / Q000175:diagnosis / Q000235:genetics*; D012307:Risk Factors; D014057:Tomography, X-Ray Computed