title: Linkage analysis and detection of somatic, postzygous RB1 mutations in Serbian retinoblastoma patients.
abstract: OBJECTIVE
  The etiology of retinoblastoma (RB) is mutational inactivation of two RB1 alleles, the prototype of tumor suppressor gene. The aim of this research was to reveal sporadic, postzygous RB1 gene mutations, in particular loss of heterozygosity (LOH), from formalin-fixed, paraffin-embedded tumor samples in RB patients, as well as tracking RB1 allele inheritance in 10 RB families.
  
  
  METHODS
  The mutational studies were carried out in the peripheral blood lymphocytes' DNA of 4 bilateral and 12 unilateral RB patients and DNAs from tumors from 3 bilateral and 10 unilateral patients. Tumor samples were collected from the same patients whose blood was analyzed. DNA was extracted and linkage analysis and microsatellite markers method were performed. LOH for two RB1 intragenic markers was analyzed.
  
  
  RESULTS
  Ten LOH were found in the area of two intragene microsatellite loci. Linkage analysis revealed inheritance of RB1 alleles in 10 families. LOH was found in 63.16% of tumors.
  
  
  CONCLUSIONS
  Peripheral blood lymphocytes' DNA gives better results as a control group for somatic mutations than DNA isolated from eye tissue outside the tumor. Linkage analysis is essential for identifying the individual risk, offering the possibility of an adequate genetic counseling in familial RB.
authors.affiliation: Institute of Lung Diseases, Clinical Center of Serbia, Belgrade, Serbia. milicakontic@yahoo.com
authors.forename: M
authors.initials: M
authors.lastname: Kontic
authors.forename: I
authors.initials: I
authors.lastname: Palacios
authors.forename: M
authors.initials: M
authors.lastname: Kontic
authors.forename: J
authors.initials: J
authors.lastname: Alonso
authors.forename: A
authors.initials: A
authors.lastname: Pestana
mesh_terms: D008040:Genetic Linkage; D006801:Humans; D019656:Loss of Heterozygosity; D009154:Mutation; D019572:Retinal Neoplasms / Q000235:genetics*; D012175:Retinoblastoma / Q000235:genetics*; D016160:Retinoblastoma Protein / Q000235:genetics*; D055771:Serbia
chemical_list: D016160:Retinoblastoma Protein