RESUMO
OBJECTIVES: Early diagnosis of unbalanced chromosomal abnormalities can be crucial in minimizing the trauma caused by an elective abortion. Chorionic villus sampling (CVS) can be performed from 9 weeks of gestation. However, two major problems are encountered in fetal karyotyping using cultured cells from chorionic villi: the relatively slow growth of these cells in culture, which delays the diagnosis, and the occurrence of maternal cell contamination (MCC). With FISH, a result can be obtained within 24 h, and, as no cell culturing is involved, the problem of MCC is minimized. METHODS: Thirty-two women undergoing CVS between 9 and 12 weeks of gestation were offered FISH analysis in addition to the standard chromosome analysis. RESULTS: FISH was informative in all of the cases tested. Eleven aneuploidies were detected in cases of hygroma or abnormal nuchal translucency and two out of four fetuses from parental translocation were unbalanced. The decision to perform early termination of these chromosomally abnormal pregnancies was based on FISH results and ultrasound abnormalities, without waiting for karyotype results. CONCLUSION: The present study confirms that the association of FISH and CVS allows a rapid and early prenatal diagnosis, and emphasizes that this association is of great benefit in cases of known parental balanced translocation or when hygroma is detected by ultrasonography.
Assuntos
Amostra da Vilosidade Coriônica , Aberrações Cromossômicas , Idade Gestacional , Hibridização in Situ Fluorescente , Diagnóstico Pré-Natal/métodos , Aneuploidia , Feminino , Humanos , Cariotipagem , Linfangioma Cístico/genética , Pescoço/diagnóstico por imagem , Pescoço/embriologia , Gravidez , Primeiro Trimestre da Gravidez , Translocação Genética , Ultrassonografia Pré-NatalRESUMO
We describe an interphase FISH analysis for formol-fixed, paraffin-embedded tissue sections with commercial probes detecting the t(11;14)(q13;q32) in mantle cell lymphoma and the t(8;14)(q24;q32) in Burkitt's lymphoma. Staining of an adjacent section allowed identification of tumoral areas. The cut-off value was evaluated in reactive lymph nodes at 5% for both probes. An incomplete hybridization pattern was found in 18 to 26% of the nuclei but was always lower than the percentages of translocated cells in tumoral regions. A t(11;14) was detected in 4/4 mantle cell lymphomas and a t(8;14) in 2/3 Burkitt's lymphomas. Interphase FISH analysis of fixed-tissue sections is a reliable technique for the direct detection of lymphoma-associated translocations on routine histological material.