Studies of Mosaicism for Chromosomal Aneuploidy in Fetal Loss Using Fluorescence In Situ Hybridization on Several Tissue Types

Abstract

The main objective ofthis study was to determine the presence and level of mosaicism for chromosomal aneuploidy in several cases of fetal demise that had previous indications of chromosome aberrations. The presence of aneuploidy was determined using fluorescence in situ hybridization (FISH) probes. Techniques that were utilized in attempts to prepare several tissue types for FISH are described. The analyses made with FISH provided useful data on the chromosomal makeup oftwo of the cases studied. In one case FISH results showed that the product of conception (POC) did not contain the trisomy 18 that is present at low levels in the mother’s blood cells. In the other case the miscarried fetus was previously identified as being mosaic for trisomy X. In this research project the presence ofvarying levels of trisomy X in both embryonic and placental tissue was confirmed