TrophoTest , a new non-invasive approach to prenatal diagnosis using in vitro culture of trophoblasts isolated from maternal blood – TROPHOTEST

Prenatal diagnosis includes a screening phase which must be considered by ethic regulatory and a diagnosis phase which are invasive procedures such as collection of trophoblasts or amniocentesis, which include for each of them, risk complications for mother and fetus. The risk of fetal loss is estimated between 0.5 and 2%. Given these risks, these procedures are applied only in case of high risk of genetic or chromosomic abnormality.

For many years, noninvasive approaches to the diagnosis Prenatal have grew and resulted of a better sensitivity of screening without providing a diagnosis as reliable as the karyotype.

With advances in molecular biology, the presence of fetal DNA circulating in maternal blood was confirmed and the research on detection of the latter in particular the DNA sequencing is promoted and applied to prenatal diagnosis.

Thus remains the gold standard for diagnosis is obtaining a genetic material or karyotyping after isolation and culture of fetal cells, ie circulating trophoblast cells.

This new approach has led to considerable progress without reaching the level of sensitivity required for a diagnosis of aneuploidy in clinical applications.
After numerous attempts to isolate and characterize these cells, a renewed interest is focused to the possibility of isolate on a suitable filter and maintaining of trophoblastic cells in culture to perform karyotyping and obtain genetic material of high quality giving access, among others, to high throughput sequencing.

In this proposal, we provide the expertise of different complementary teams in clinical and biology, to develop an ambitious and original project in the context of prenatal diagnosis.

Our preliminary work has allowed identifying trophoblastics cells and maintaining them in culture in order to perform a karyotyping.

The first aims will be to study the kinetics of appearance of these cells fetal origin according to the terme, from the first quarter and from pregnancies obtained after in vitro fertilization (perfectly dated).

The second aims concerne for patients at high risk of birth with of disorder chromosomal, for which we will compare the results by our non-invasive method with those obtained by chorionic punction or amniocentesis.

These two objectives will allow us to propose in a future an access to the earliest possible prenatal diagnosis of certainty during pregnancy.