Discordant karyotypes in CVS and amniocenteses using cytogenetic and fluorescence in situ hybridization (FISH) analyses

Single Nucleotide Polymorphism-Based Analysis of Cell-Free Fetal DNA in 3000 Cases from Germany and Austria

“…The cell-free fetal DNA source for NIPT analysis is derived from placental cells [21]. Thus, analysis of aneuploidies by NIPT faces similar problems as in chorionic villi sampling (CVS), in which a discrepancy between embryoblast and trophoblast is observed in 1-2 % of cases [15][16][17][18]. CPM is especially common in trisomy 18 and 13 placentas [19].…”

A prospective comparative study on fluorescencein situ hybridization (FISH) of uncultured amniocytes and standard karyotype analysis

“…Low grade mosaicisms may be misinterpreted when the percentage of aneuploid cells is below 10 per cent of counted nuclei (due to the chosen cut-off level). On the other hand, specific disadvantages of other methods, e.g., CVS, can be avoided by performing the FISH assay difectly on embryonic tissue and not on the trophoblast as demonstrated by the case of triploidy (Eiben et al, 1998a) in which the aberrant cell line was detected in amniocytes but not in the villi. This particular case demonstrates the dilemma arising from discrepancies between trophoblast and embryonic cells and the importance of amniocentesis, especially in cases with abnormal ultrasound (Kennerknecht et al, 1993).…”

False-negative finding in rapid interphase FISH analysis of uncultured amniotic cells

“…Even with conventional amnion culture, extremely rare cases of discrepancies have been reported. We have observed two discrepancies between CVS/short-term culture and amniocentesis/rapid FISH: one false negative for trisomy 18 and one for triploidy an chorionic villi were detected in amniocytes by FISH (Eiben et al, 1998b). So, in every case of diagnosis using 'fast systems', like CVS and short-term culture or rapid FISH analyses, a second diagnostic parameter (longterm culture of chorionic villi/amniotic cells and/or sonographical findings) has to be considered before final decisions are made.…”