A molecular study of first and second RB1 mutational hits in retinoblastoma patients
Andrade, Ana Fl via Belchior de; Barbosa, Raquel da Hora; Vargas, Fernando Regla; Fermanb, Sima; Fernandes, Luisa; Eisenberg, Ana L£cia; Bonvicino, Cibele R.
Cancer Genet Cytogenet
; 167(1): 43-46, May, 2006. tab
Artículo
en Inglés
| TXTC | ID: txt-23810
RB1 mutations accountable for biallelic inactivation are crucial events in the development of retinoblastomabecause a first mutation (M1) predisposes to retinoblastoma while a second mutation(M2) is required for tumor development. Mutational analyses of this gene showed a wide spectrumof genetic alterations (single base substitutions, insertions, or deletions, as well as small and largedeletions). The most frequent second hit in retinoblastoma patients is loss of heterozygosity (LOH)followed by promoter methylation. Molecular analyses of RB1 mutations were conducted in 36patients (20 unilateral and 16 bilateral) using polymerase chain reactionmediated single-strandconformation polymorphism (SSCP) analysis, sequencing, and LOH analysis. Sixty-four amplifiedfragments showing abnormal SSCP patterns were sequenced, and mutations were confirmed in fivepatients (13.89%). Four mutations were located at coding regions, and a fifth one was found at anexonintron junction. Two mutations were C/T transitions, two were small-length deletions, andone was a G/A transition. A total of 47.05% patients showed LOH. In one patient, the parentalorigin of the mutated allele was detected the allele retained in the tumor was the paternal one. Thiswork helps to characterize the spectrum of mutations in the Brazilian population, and to confirmthat formaldehyde-fixed paraffin tissue can provide valuable information on the RB1 status inretinoblastoma patients.(AU)
Biblioteca responsable:
BR440.1
Ubicación: BR440.1
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