title: PCR detection of Xbal polymorphism in the human Rb gene of retinoblastoma patients.
abstract: Inactivation of the Rb (retinoblastoma) tumor suppressor gene is associated with hereditary and sporadic cases of retinoblastoma and other Rb-related tumors. Early diagnosis and genetic counseling heavily depend on practical methods for the detection of Rb deletions and mutations in high-risk families. Here we report on the use of a pair of primers in polymerase chain reaction (PCR) to amplify a 945-bp fragment from intron 17 of the Rb gene (T.L. McGee, G.S. Cowley, D.W. Yandell and T.P. Dryja, 1990, Nucleic Acid Research, 18: 207). Xbal digestion of the PCR product reveals 2 allelic versions: a single 945-bp fragment (allele 1) or 2 fragments of 315 and 630 bp (allele 2). We used total genomic DNA (blood and tumors) to investigate the power of this PCR-Rb-Xbal-RFLP in the identification of both segregation and loss of heterozygosity of the Rb gene. In one family studied (family 1A) in which 2 generations were affected, it was possible to localize the mutated Rb gene to Xbal-Rb allele 2. The assay of loss of heterozygosity of the Rb gene is available for all Xbal-Rb allele 1-2 individuals, so that analyses may be applied in large scale investigation of the participation of Rb gene in tumor development. We conclude that PCR-Rb-Xbal-RFLP is a practical and powerful tool for oncology research and genetic counseling.
authors.affiliation: Departamento de Histologia e Embriologia, Universidade de São Paulo, Brasil.
authors.forename: E
authors.initials: E
authors.lastname: Costanzi
authors.forename: C M
authors.initials: CM
authors.lastname: Erwenne
authors.forename: M C
authors.initials: MC
authors.lastname: Armelin
mesh_terms: D005134:Eye Neoplasms / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D016161:Genes, Retinoblastoma / Q000235:genetics*; D006580:Genetic Carrier Screening; D006801:Humans; D007438:Introns / Q000235:genetics; D008297:Male; D010375:Pedigree; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length; D012175:Retinoblastoma / Q000235:genetics*