[Detection or exclusion of fetal trisomy 18 by in-situ-hybridization of the histologic section].

In-situ-hybridization using a chromosome-specific centromeric DNA probe on paraffin embedded tissue of placental and foetal origin allows the detection of numerical chromosome anomalies, even after several years. This may facilitate the diagnosis of late abortions in those cases in which a conventional cytogenetic examination was not performed, but the clinical picture suggests a chromosomal syndrome. We demonstrate chromosome DNA fluorescence in-situ-hybridisation (FISH) with a chromosome 18 specific (peri) centromeric repeat probe, on paraffin sections of one case with a cytogenetically proven and of three cases with a questionable Edwards-syndrome, thus confirming or excluding trisomy 18 in two of the cases.