[Clinical application of fluorescence in situ hybridization to prenatal diagnosis]

Fluorescence in situ hybridization (FISH) allows rapid and accurate detection of not only numerical aberrations but also molecular rearrangements not detectable and identifiable by conventional cytogenetic techniques. In this study, two commercially available DNA probes (Chromoprobe-I 18 and 13/21) were used for direct analysis of uncultured amniocytes. These directly labelled probes proved to be useful for determining the number of copies of specified chromosomes in interphase nuclei from individual cells. However, mosaic results obtained with the 13/21 probe in the interphase nuclei may not always be clearcut, suggesting the necessity of reference to control samples. FISH should become more practical and effective strategy for rapid prenatal confirmation of potential aneuploidies indicated by triple marker screening of maternal serum and ultrasound findings.