Human Genetics

, Volume 92, Issue 4, pp 353–358

Detection of confined placental mosaicism in trisomy 18 conceptions using interphase cytogenetic analysis

Authors

  • Karen J. Harrison
    • Research DivisionBritish Columbia's Children's Hospital
  • Irene J. Barrett
    • Department of PathologyUniversity of British Columbia
  • Brenda L. Lomax
    • Department of PathologyUniversity of British Columbia
  • Brian D. Kuchinka
    • Cytogenetics and EmbryopathologyBritish Columiba's Cildren's Hospital
  • Dagmar K. Kalousek
    • Cytogenetics and EmbryopathologyBritish Columiba's Cildren's Hospital
    • Department of PathologyUniversity of British Columbia
Original Investigations

DOI: 10.1007/BF01247334

Cite this article as:
Harrison, K.J., Barrett, I.J., Lomax, B.L. et al. Hum Genet (1993) 92: 353. doi:10.1007/BF01247334

Abstract

Fluorescence in situ hybridization provides a rapid and accurate technique for detecting chromosomal aneuploidy. It is an excellent method for identifying mosaicism in placental tissues following prenatal diagnosis. Mosaicism, in the form of confined placental mosaicism, occurs im approximately 1%–2% of viable pregnancies studied by chorionic villus sampling at 9–11 weeks of gestation. It has been detected in pregnancies with both diploid and trisomic fetuses and appears to have an important effect on the intrauterine fetal survival. Using both standard cytogenetic analysis and fluorescence in situ hybridization, we have studied 12 placentas from pregnancies with trisomy 18 for the presence of chromosomal mosaicism. These included 2 that were spontaneously aborted, 5 that were terminated after prenatal diagnosis, and 4 that were delivered as either stillborn or liveborn. Significant levels of mosaicism, confined exclusively to cytotrophoblast, were detected in 7 pregnancies. This study demonstrates the usefulness of interphase cytogenetic analysis of uncultured tissues as an alternative method for the detection of mosaicism.

Copyright information

© Springer-Verlag 1993