RESUMO
This cytogenetic study deals with a family in which some members are carriers of 15p+ polymorphism variant, with an unusually elongated short arm. The chromosomal marker segregates in three generations, duplicating its length but without phenotypic manifestation in the carriers. An analysis by using banding techniques shows us the characteristics of the p+ region and its transmission within the family.
Assuntos
Aberrações Cromossômicas/genética , Cromossomos Humanos Par 15 , Citogenética , Feminino , Marcadores Genéticos , Variação Genética , Heterocromatina , Heterozigoto , Humanos , Linhagem , Fenótipo , Polimorfismo Genético , Gravidez , Diagnóstico Pré-NatalRESUMO
We report a case of familiar retinoblastoma, in which both mother and daughter show bilateral retinoblastoma. The cytogenetic study, in both peripheral blood lymphocytes and tumoral tissue did not show alterations on the 13 chromosome, although we found a complex kariotype in tumoral tissue defined by three celular lines. In all of them appears a marker in which the 6 chromosome is involved (der 6). The derivated of 6 chromosome are markers highly characteristic of the retinoblastoma cases, and can be related with the aggressivity of tumor and the appearance of the second tumors.
