OBJECTIVE: To contribute to the risk assessment of true fetal mosaicism after detection of a mosaic chromosomal anomaly in chorionic villus samples (CVS) in order to enable more effective counseling and pregnancy management. METHODS: We retrospectively reviewed 7112 consecutive CVS analyzed on both direct preparations and cultured cells. In 135 out of the 177 cases of mosaicism, we performed cytogenetic follow-up and determined the frequency of confined placental mosaicism (CPM) and true fetal mosaicism according to type and distribution of the cytogenetic abnormality. RESULTS: True fetal mosaicism was detected in 38 out of 135 cases (28.15%), confirming the higher incidence of CPM (71.85%). Confirmation rate of CV mosaicism depends on the combination of placental cell lineages affected, chromosome involved and mosaic versus non-mosaic chromosomal anomaly. The overall probability of fetal involvement significantly rises with involvement of mesenchymal cells: 5.88% abnormal cytotrophoblast, 20.96% abnormal mesenchyme and 58.97% anomalies in both tissues. CONCLUSION: Most of the mosaic findings at CVS are unreliable indicators of the fetal karyotype. Our study contributes to large series with cytogenetic information from the different tissues along the cytotrophoblast-extraembrional mesoderm-fetus axis in order to infer clinical relevance of the findings and to enable more effective genetic counseling.
OBJECTIVE: To contribute to the risk assessment of true fetal mosaicism after detection of a mosaic chromosomal anomaly in chorionic villus samples (CVS) in order to enable more effective counseling and pregnancy management. METHODS: We retrospectively reviewed 7112 consecutive CVS analyzed on both direct preparations and cultured cells. In 135 out of the 177 cases of mosaicism, we performed cytogenetic follow-up and determined the frequency of confined placental mosaicism (CPM) and true fetal mosaicism according to type and distribution of the cytogenetic abnormality. RESULTS: True fetal mosaicism was detected in 38 out of 135 cases (28.15%), confirming the higher incidence of CPM (71.85%). Confirmation rate of CV mosaicism depends on the combination of placental cell lineages affected, chromosome involved and mosaic versus non-mosaic chromosomal anomaly. The overall probability of fetal involvement significantly rises with involvement of mesenchymal cells: 5.88% abnormal cytotrophoblast, 20.96% abnormal mesenchyme and 58.97% anomalies in both tissues. CONCLUSION: Most of the mosaic findings at CVS are unreliable indicators of the fetal karyotype. Our study contributes to large series with cytogenetic information from the different tissues along the cytotrophoblast-extraembrional mesoderm-fetus axis in order to infer clinical relevance of the findings and to enable more effective genetic counseling.
Authors: Diane Van Opstal; Merel C van Maarle; Klaske Lichtenbelt; Marjan M Weiss; Heleen Schuring-Blom; Shama L Bhola; Mariette J V Hoffer; Karin Huijsdens-van Amsterdam; Merryn V Macville; Angelique J A Kooper; Brigitte H W Faas; Lutgarde Govaerts; Gita M Tan-Sindhunata; Nicolette den Hollander; Ilse Feenstra; Robert-Jan H Galjaard; Dick Oepkes; Stijn Ghesquiere; Rutger W W Brouwer; Lean Beulen; Sander Bollen; Martin G Elferink; Roy Straver; Lidewij Henneman; Godelieve C Page-Christiaens; Erik A Sistermans Journal: Genet Med Date: 2017-09-28 Impact factor: 8.822
Authors: Diane Van Opstal; Malgorzata I Srebniak; Joke Polak; Femke de Vries; Lutgarde C P Govaerts; Marieke Joosten; Attie T J I Go; Maarten F C M Knapen; Cardi van den Berg; Karin E M Diderich; Robert-Jan H Galjaard Journal: PLoS One Date: 2016-01-15 Impact factor: 3.240