Prenatal Screening for Imprinting Anomalies Implicated in Beckwith Wiedemann and Silver Russell Syndromes (DASIRUWIBE)
Losses of imprinting are involved in various syndromes. Those occurring in the 11p15 region lead to Beckwith-Wiedemann and Silver-Russell Syndromes. These losses of imprinting follow a mosaic pattern, rendering their detection difficult, especially given the scarcity of available DNA in amniotic fluid. Thus, in spite of growing demand, prenatal diagnosis (PND) for imprinting abnormalities of the 11p15 region is not available.
The recent development of a quantitative PCR method that permits the methylation index (MI) of imprinted regions to be calculated renders PND technically possible. Nevertheless, because of the mosaic nature of these anomalies, it is essential to verify that the methylation pattern of the 11p15 region obtained from the amniotic fluid matches that obtained from the blood.
|Study Design:||Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
|Official Title:||Prenatal Screening for Imprinting Anomalies Implicated in Beckwith Wiedemann and Silver Russell Syndromes|
- Methylation Index (MI) of the 11p15 region using DNA extracted [ Time Frame: 27 weeks ]To evaluate the agreement between the MI of the 11p15 region obtained using DNA extracted from amniocytes and that extracted from cord blood leukocytes, by calculating the intraclass correlation coefficient (ICC).
- MI using the placenta [ Time Frame: 27 weeks ]To calculate the MI using the placentas of the same individuals and to evaluate its agreement with the MIs obtained above.
|Study Start Date:||May 2013|
|Estimated Study Completion Date:||October 2016|
|Primary Completion Date:||December 2015 (Final data collection date for primary outcome measure)|
Experimental: Pregnant women requiring amniocentesis
Pregnant women requiring amniocentesis
Genetic: Methylation Index
To calculate the methylation index (MI) of imprinted regions.
To evaluate the agreement between the methylation index of the 11p15 region obtained using DNA extracted from amniocytes and that extracted from cord blood leukocytes, by calculating the intraclass correlation coefficient (ICC).
Ancillary study :
This second part of the study aims to determine the standard of methylation index of the 11p15 region (inclusion of 100 additional patients). The use of amniotic liquid will allow to calculate :
- the average of methylation index,
- the value of the standard deviation
- the inter-assay coefficient of variation for the test-used.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01842659
|Explorations fonctionnelles endocriniennes|
|Paris, France, 75012|
|Principal Investigator:||Irene Netchine, PU-PH||Assistance Publique|