In situ hybridization studies for the detection of common aneuploidies in CVS.

We have attempted to evaluate the efficiency of interphase cytogenetics in the detection of specific aneuploidies in chorionic villus samples. For this purpose, we used alphoid repetitive sequences specific for the chromosomes involved in the common aneuploidies, namely probes for chromosomes 13, 18, 21, X, and Y. These probes were applied to normal and abnormal CVS cases, as well as to a few mosaic cases. Results from these preliminary studies indicate that the technique can be very efficient for the detection of specific aneuploidies and can be particularly useful in the analysis of mosaic cases, which usually requires the screening of a high number of metaphases.