Non-invasive Screening of Fetal Trisomy 21 by Digital PCR (dPNI-T21)

July 27, 2021 updated by: University Hospital, Caen

In France, as in many countries of the world, trisomy 21 or Down syndrome (DS) is the subject of an antenatal screening based on a risk calculation (R) including the assay of biochemical markers in the maternal blood, and the measurement of a fetal ultrasound parameter (nuchal translucency). In the population of pregnant women said to be at high risk (R> 1/250), confirmation of the diagnosis of DS is made by invasive sampling (trophoblast biopsy or amniocentesis), which allows the establishment of fetal karyotype. In addition to limited sensitivity (80 to 85% depending on the techniques), this screening is an anxiety factor (8% false positives), and miscarriages of euploid fetuses (normal karyotype) in 1% of cases (procedures invasive).

The plasma of a pregnant woman contains a mixture of free DNA of maternal (90%) and fetal origin (cffDNA for cell free fetal DNA) (about 10%, but this proportion increases in cases of fetal trisomy 21. The proportion of cffDNA is sufficient to qualitatively and quantitatively study specific genetic markers of a pair of chromosomes. It is therefore possible to evaluate the quantity of markers chromosome of interest relative to a reference chromosome marker, and to calculate a marker / marker ratio of interest, theoretically identical for all autosomes (chromosomes 1 to 22) during euploid pregnancy. In case of fetal aneuploidy (for example, trisomy 21), this ratio is unbalanced for the chromosomal pair involved.

Advances in technology, such as high-throughput mass sequencing (MPS) and digital PCR (dPCR), now make it possible to consider the diagnosis of fetal maternal DS through the study of cffDNA. Several teams have already published on this subject with the MPS technique, applied directly to free DNA from maternal plasma, or after a cffDNA isolation step. This involves sequencing the DNA fragments present in the sample and placing them back on their original chromosome. In case of trisomy 21 fetal, one seeks to put in evidence of an excess of sequences from chromosome 21. These techniques require expensive equipment (sequencer, bioinformatic platform, servers) and a technical time and important analysis (often several days for a single run). Concerning the research of aneuploidies by digital PCR (dPCR), few publications are today due to the absence of sufficiently powerful instruments until recently. DPCR is less expensive.

Study Overview

Status

Terminated

Conditions

Study Type

Observational

Enrollment (Actual)

776

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Caen, France, 14033
        • Arnaud Molin

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

Women with high risk of fetal trisomy 21 with maternal screening test, who benefited of invasive sampling (chorionic villi or amniotic fluid) and karyotype

Description

Inclusion Criteria:

  • Women with high risk of fetal trisomy 21 with maternal screening test, who benefited of invasive sampling

Exclusion Criteria:

  • women with twin pregnancies
  • pregnancies with other chromosomal abnormalities

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
feasibility of non invasive prenatal testing with digital PCR
Time Frame: 3 years
3 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (ACTUAL)

January 1, 2013

Primary Completion (ACTUAL)

September 1, 2015

Study Completion (ACTUAL)

December 1, 2018

Study Registration Dates

First Submitted

September 5, 2016

First Submitted That Met QC Criteria

September 24, 2018

First Posted (ACTUAL)

September 27, 2018

Study Record Updates

Last Update Posted (ACTUAL)

July 28, 2021

Last Update Submitted That Met QC Criteria

July 27, 2021

Last Verified

November 1, 2017

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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