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Prenatal Screening for Imprinting Anomalies Implicated in Beckwith Wiedemann and Silver Russell Syndromes

Not Applicable
Conditions
Pregnant Women Requiring Amniocentesis
Interventions
Genetic: Methylation Index
Registration Number
NCT01842659
Lead Sponsor
Assistance Publique - Hôpitaux de Paris
Brief Summary

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.

Detailed Description

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.

Recruitment & Eligibility

Status
UNKNOWN
Sex
Female
Target Recruitment
67
Inclusion Criteria
  • Pregnant women, 18 years of age or older
  • Requiring amniotic fluid sampling in the context of pregnancy care after 15 weeks of amenorrhea
  • Having provided written informed consent
  • Followed at Trousseau Hospital or Clinique des Bluets during their pregnancy
  • Covered by or beneficiary of a state health insurance program (except for medical aid programs)
Exclusion Criteria
  • Warning signs on ultrasound that require a medical termination of pregnancy to be discussed even before amniocentesis is performed

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Pregnant women requiring amniocentesisMethylation IndexPregnant women requiring amniocentesis
Primary Outcome Measures
NameTimeMethod
Methylation Index (MI) of the 11p15 region using DNA extracted27 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).

Secondary Outcome Measures
NameTimeMethod
MI using the placenta27 weeks

To calculate the MI using the placentas of the same individuals and to evaluate its agreement with the MIs obtained above.

Trial Locations

Locations (1)

Explorations fonctionnelles endocriniennes

🇫🇷

Paris, France

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