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Pictogramme horloge October 2014

Non-invasive prenatal screening

The discovery of foetal DNA in maternal blood combined with a new and very-high output sequencing method – NGS (Next Generation Sequencing), has opened numerous perspectives in the field of foetal medicine. One of the main expected applications is non-invasive Down’s syndrome screening (trisomy 21 – T21). For over 10 years, the analysis of foetal DNA circulating in maternal blood was routinely performed to determine foetal gender within the scope of screening for genetic diseases associated with chromosome X and the Rhesus D status of the foetus for foetal-maternal incompatibility screens. Massively-parallel sequencing allows for the development of new non-invasive prenatal screening tests (NIPT) for chromosomes 13, 18 and 21 aneuploidy. In addition to its reliability, NIPT allows for a significant decrease in invasive acts (chorionic villi sampling and amniotic fluid sampling) in women considered at risk as well as a decrease in foetal losses (approximately 1%).

Good practice

In France, the decree of 23 June 2009 defines the precise screening procedures for trisomy 21, including the assay of serum markers during the first trimester (or second trimester) combined with the nuchal translucency measurement during the ultrasound scan. In April 2013, the Comité Consultatif National d’Ethique (National Ethics Commitee) voted in favour of the implementation of trisomy 21 genetic screening for women at risk following maternal serum marker analysis. National and international obstetric and gynecology authorities gave the same verdict and defined the indications, benefits and limitations of foetal DNA analysis for T21 screening in maternal blood.

NIPT is a major break through in technological advances. Its proven reliability and interest remain unchallenged, however, its role in patient health care and in the testing decision process for first-trimester pregnancies screenings is, as yet, undefined. This is the objective of the STIC (Soutien aux Techniques Innovantes et Couteuses – Support Innovative and Costly Techniques) SAFE21 at the NECKER hospital. Biomnis actively collaborates with this team ensuring the logistics of the programme via its sample collection network.

Accredited with the required certificates to practice prenatal diagnostic activities, including cytogenetics and molecular genetics, Biomnis offers high-output sequencing technology and has a HiSeq™ 2500 Illumina analyser, thus offering the best performance for the diagnosis of Down’s syndrome (trisomy 21). Along with our support to STIC SAFE21 team, and to meet the expectations of pregnant women as well as their attending physicians, we are in a position to offer NIPT to patients considered at risk of foetal trisomy 13, 18 and 21.

In order to uphold the recommendations of good practice for prenatal diagnostics (decree number 2014-32 of 14 January 2014), the implementation of genetic testing requires informed consent from the patient.
We openly invite health care staff to contact the International Division at international@biomnis.com or +33 4 72 80 23 85 to assess your case and the use of NIPT. The referring laboratory should contact the International Division to receive your sampling kit and organise sample collection.

References