Presented at the 6th International Congress of Human Genetics, Jerusalem, September 1981, by J.L.
European collaborative study on prenatal diagnosis: Mosaicism, pseudomosaicism and single abnormal cells in amniotic fluid cell cultures†
Article first published online: 21 NOV 2005
Copyright © 1984 John Wiley & Sons, Ltd.
Special Issue: Collaborative Studies in Prenatal Diagnosis of Chromosome Aberrations
Volume 4, Issue 7, pages 145–162, November/December 1984
How to Cite
Bui, T.-H., Iselius, L. and Lindsten, J. (1984), European collaborative study on prenatal diagnosis: Mosaicism, pseudomosaicism and single abnormal cells in amniotic fluid cell cultures. Prenat. Diagn., 4: 145–162. doi: 10.1002/pd.1970040710
- Issue published online: 21 NOV 2005
- Article first published online: 21 NOV 2005
- Chromosome mosaicism;
- Prenatal diagnosis;
- European collaborative study
A report is given of the results of a European collaborative study on mosaicism, pseudomosaicism and single abnormal cells in amniotic fluid cell cultures. The mean frequency of cases with mosaicism was 0.10 per cent, with pseudomosaicism 0.64 per cent and with single abnormal cells 2.83 per cent in a series of 44 170 amniotic fluid samples. There was no significant difference between the colony (in situ) and the flask method with regard to the frequency of mosaicism. Pseudomosaicism and single abnormal cells were more frequent in cases studied with the flask method probably due to other factors than the method of cultivation of the cells.
The frequency of maternal cell contamination was 0.17 per cent and the frequency of wrong sex assignment was 0.11 per cent. A more correct estimation is obtained if these frequencies are doubled.
There was a considerable variation between laboratories with regard to the frequencies given above. One reason for this variation is that there are no sharp limits between mosaicism, pseudomosaicism and single abnormal cells. Thus the material contained cases diagnosed as having pseudomosaicism which turned out to be mosaics at birth and to have an abnormal phenotype. These cases were very rare but pose a definite problem in prenatal cytogenetic diagnosis.