New Generation of Non-Invasive Prenatal Testing Methods
Breakthrough genetic disorder determination
Prenatal tests are conducted during pregnancy to provide information about the health of the mother and her baby. Eurofins companies have pioneered work to develop improved prenatal screening tests for conditions that might affect the foetus, and help inform healthcare decisions before and after the birth.
For over 30 years, Eurofins laboratories have held leading positions in the research and development of prenatal screening protocols to help detect birth defects, genetic diseases and other conditions. For example, Eurofins laboratories were among the world’s first clinical laboratories to provide an alpha-foetoprotein screening programme. This test is known for its effectiveness in identifying a risk in the foetus for open neural tube defects.
In December 2016, Eurofins LifeCodexx launched the worldwide first non-invasive prenatal test (NIPT) assay based on a quantitative real-time PCR for prenatal testing of foetal trisomy 21 (qNIPT). The novel and proprietary qNIPT assay allows for significant cost efficiencies and speed over other classical NIPT methods as it is based on polymerase chain reaction (PCR), the most widely used platform within the molecular diagnostic space. This test’s significantly lower cost and faster processing time allows more pregnant women to opt for NIPT as a reliable and affordable prenatal testing method.
Similarly, Eurofins Biomnis was the first commercial laboratory in France to offer, in October 2014, an NIPT Next Generation Sequencing test and was also the first to validate the method on twin pregnancies.
In 2017, Eurofins Genoma unveiled a breakthrough in NIPT technology, developing, for the first time ever, an NIPT that screens for both de novo-gene mutations, that are not inherited – and inherited single-gene disorders. NIPTs are simple blood tests that were previously only able to screen for aneuploidies, errors in cell divisions which see ‘daughter’ cells having the wrong number of chromosomes, and microdeletions, which are chromosomal deletions that are too small to be detected by light microscopy and can lead to genetic disorders. More recently, NIPTs also screened for rare aneuploidies and segmental chromosome imbalances (gains and losses) in every chromosome in the foetal genome. Not only does this new Eurofins test, GeneSafe™, identify prenatal conditions which traditional prenatal testing may miss, but it also detects over 40 severe genetic disorders that might occur in the absence of any family history of the condition.
Eurofins Genoma has significant experience in performing genome-wide cfDNA screening, which can detect rare trisomies. The laboratory is able to distinguish between trisomies that are likely confined to the placenta (resulting in a false positive result which decreases the specificity of the test) from true trisomies (which are confirmed to be in the foetus).
The test is also the first ever NIPT to detect disorders with an increased likelihood associated with paternal age, something particularly useful as later-stage parenthood is increasingly common.
Apart from NIPT tests performed during pregnancy, Genoma also developed one of the first non-invasive preimplantation genetic aneuploidy screening tests, so a test that is used to exclude chromosomic aberrations of embryos for assisted reproductive technologies.
The science behind
Based on quantitative real-time PCR rather than on Next Generation Sequencing, the qNIPT foetal trisomy 21 test from Eurofins LifeCodexx is not only cheaper, but also significantly faster. Due to different methylation patterns of specific gene regions of the maternal and foetal DNA, positive and negative samples can be distinguished and the test provides rapid results in two to three days under the highest quality standards.
The GeneSafe™ test is intended for patients who had an abnormal ultrasound finding which was suggestive of some form of monogenic disorder. The technology screens for new mutations that are common and cannot be detected by standard carrier screening, as these mutations are not present in the parents.
While traditional NIPT screens for conditions typically associated with advanced maternal age (e.g. Down syndrome), GeneSafe™ also screens for genetic disorders that are associated with advanced paternal age (men that are over 40 years old), ensuring a more comprehensive screen for couples of advanced age.
