title: [Clinical applications of molecular diagnosis of retinoblastoma ain 15 families].
abstract: OBJECTIVE
  In 40% retinoblastoma (Rb) results from a hereditary mutation of the Rb susceptibility gene (RB1). In this study, we tested the usefulness of intragenic DNA analysis for ophthalmologic follow-up in affected families.
  
  
  METHODS
  Molecular analysis was performed on 103 DNA samples of 15 Rb families. We used 7 intragenic polymorphic markers and one within the ESD gene for mutation linkage analysis.
  
  
  RESULTS
  DNA analysis was informative in 88% of relatives at risk of developing Rb. Among them, the presence of a mutated RB1 allele was excluded in 46%, while 29% were unaffected carriers and 25% had inherited the Rb predisposition.
  
  
  CONCLUSIONS
  In the majority of familial Rb, the DNA analysis allows the identification of children carrying a RB1 mutation and who will need a close ophthalmologic follow-up under general anesthesia. When the mutated gene is absent, ophthalmological examination under narcosis is unnecessary. Finally, identification of asymptomatic carriers improve the accuracy of genetic counselling.
authors.affiliation: Hôpital Ophtalmique Jules Gonin, Lausanne.
authors.forename: B
authors.initials: B
authors.lastname: Lendi
authors.forename: G
authors.initials: G
authors.lastname: Pescia
authors.forename: F
authors.initials: F
authors.lastname: Thonney
authors.forename: A
authors.initials: A
authors.lastname: Balmer
authors.forename: F
authors.initials: F
authors.lastname: Munier
mesh_terms: D000328:Adult; D000483:Alleles; D002648:Child; D004252:DNA Mutational Analysis; D005134:Eye Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000517:prevention & control; D005260:Female; D006580:Genetic Carrier Screening; D005817:Genetic Counseling; D006801:Humans; D007223:Infant; D008297:Male; D010375:Pedigree; D012150:Polymorphism, Restriction Fragment Length; D012175:Retinoblastoma / Q000175:diagnosis / Q000235:genetics* / Q000517:prevention & control; D012307:Risk Factors