Cytogenetic results of chorionic villus sampling: High success rate and diagnostic accuracy in the United States collaborative study

Cytogenetic Evaluation of 1000 Cases of Chorionic Villus Sampling

“…[17][18][19][20] The incidence of level II and III mosaicism in our study was comparable to that reported in other large CVS collaborative studies. [3][4] Although the incidence of level III mosaicism was much higher than in amniocentesis (0.9% vs. 0.25%), the follow-up normal result with a normal outcome in all 13 cases in our study is reassuring that many of the low-level III mosaic findings in CVS are most likely due to CPM. Nevertheless, follow-up amniocentesis should be recommended in level III mosaic findings in CVS, irrespective of their percentage in the analysis.…”

“…[14][15][16] The cytogenetic analysis success rate of 99.6% obtained in the first attempt is comparable to other reports. 3 Through repeat CVS of failed samplings, the success rate reached 100%. One case of full trisomy 16 without any normal cells was observed, which turned out to be a false-positive.…”

“…A number of large collaborative studies throughout the world have documented the safety of the CVS procedure. [1][2][3][4][5] However, Ledbetter et al 3 observed a nonsignificant increase of 0.5% to 0.8% in pregnancy loss rate in the CVS group compared to the amniocentesis group. 3 Contradictory findings of limb reduction associated with CVS have also been reported.…”

“…[1][2][3][4][5] However, Ledbetter et al 3 observed a nonsignificant increase of 0.5% to 0.8% in pregnancy loss rate in the CVS group compared to the amniocentesis group. 3 Contradictory findings of limb reduction associated with CVS have also been reported. [6][7][8][9] Based on the current data, it has been determined that CVS performed after 10 weeks of gestation, in the first trimester, is a safe, accurate and reliable prenatal test for detecting cytogenetic abnormalities.…”

Uniparental Disomy and Genome Imprinting: an Overview

“…Trisomy rescue may occur in two distinct ways at the first zygotic cleavage by chromatid nondisjunction at metaphase or chromosome lag at anaphase, or at various stages thereafter by the same mechanisms, with the initial zygotic makeup preserved in one stem cell. Figure 2 illustrates how trisomy rescue may operate [8,9,[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] by reduction to disomy according to two distinct mechanisms, both of which can generate mosaicism, in theory at least [38][39][40][41][42][43][44][45].…”