Extra embryonic/fetal karyotypic discordance during diagnostic chorionic villus sampling |
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| Authors: | Dr D F Callen G Korban G Dawson L Gugasyan E J M Krumins S Eichenbaum J Petrass S Purvis-Smith A Smith G Den Dulk N Martin |
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| Institution: | 1. Genetics Department, The Queen Elizabeth Hospital, South Australia;2. Cytogenetics Unit, Monash Medical Centre, Victoria;3. Cytogenetics Unit, Department of Pathology, Royal Women's Hospital, Victoria;4. Cytogenetics Unit, Prince of Wales Hospital, New South Wales;5. Cylogenetics Unit, Oliver Latham Laboratories, New South Wales;6. Cytogenetics Unit, Royal Brisbane Hospital, Queensland, Australia |
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| Abstract: | From a total of 1312 diagnostic chorionic villus samplings (CVS) there were 22 which showed discordance between the karyotype of the chorionic villi and that of the fetus. This frequency was some 20-fold higher than that reported at amniocentesis. In the majority of discordant cases, the fetal karyotype was normal while the placenta! karyotype was mosaic. In four cases, the placenta! karyotype was non-mosaic (a trisomy 16, a monosomy X, and two tetraploids) while the fetal karyotype was normal. In one case, the placenta was trisomy 18 while the fetus was mosaic. There were two ‘false-negative’ results where short-term methods showed only normal cells while both long-term cultures of chorionic villi and fetal cells were mosaic, in one 46,XY/47.XXY and in the other 46,X Y/47.X Y, + 21. |
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| Keywords: | Prenatal diagnosis Chorionic villus sampling Chromosomal mosaicism Cytogenetic reliability |
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