Diagnosis of numerical chromosomal aberrations in the cells of spontaneous abortions by multicolor fluorescence in situ hybridization (MFISH)

According to different estimates, as high as 15-20% of all the pregnancies result in spontaneous abortions (SA) at different gestational periods. Identification of abnormalities leading to SA is of great importance for practical medicine, mainly for medical genetic counseling of married couples with impaired reproductive function. The diagnosis of chromosomal aberrations on the basis of SA materials is known to have a number of methodological difficulties. The present paper deals with the identification of numerical anomalies in the SA material by multicolor fluorescence in situ hybridization (MFISH). This technique using an original collection of DNA probes for chromosomes 1, 9, 13/21, 14/22, 15, 16, 18, X, and Y was applied to the study of chromosomal aberrations in 224 spontaneous abortion specimens. Numerical chromosomal aberrations were found in 122 (54.5%) cases. The cells of all the studied specimens exhibited aneuploidy of chromosome X in 17% cases; chromosome 16 in 12%, chromosomes 13/21 in 5.8%, chromosomes 14/22 in 4.9%, chromosomes 9 and 18 in 1.3% (each), chromosome 15 in 0.9%, chromosome 1 in 0.45%. Polyploidy was detected in 13.3% of cases; concomitant abnormalities were found in 7 cases. Analysis of the findings has led to the conclusion that MFISH can be successfully used in the diagnosis of numerical chromosomal aberrations of CA cells.