Cytogenetic changes analysis and their role in early diagnosis on retinoblastoma
Retinoblastoma (Rb) is a rare intraocular tumour developing from immature retina cells. It is caused by a mutation oncosupressor gene-Rbl, localised in the proximal sector of a long arm of chromosome 13. Cytogenetic researches of blood in patients with retinoblastoma have revealed the specific chromosomal aberrations which level exceeds several times the indicators of healthy people (11.2% in patients, 1.2% in healthy people). In healthy relatives of patients, the level of chromosomal aberrations was 4.6%. The frequency of occurrence of specific chromosomes aberrations (13q-) in Rb patients was 16.7% (5/30), in their sibs - 5.1%. The analysis of chromosomal infringements in lymphocytes at an earlier stage of tumour development allows to define the risk of its development, for example in healthy sibs of patients with retinoblastoma.