Principal of NIPT
Cell-free DNA fragments (cfDNA) are short fragments of DNA, which can be found circulating in the blood. During pregnancy, cfDNA fragments originating from both the mother and fetus are present in the maternal blood circulation.
NIPT requires taking a small amount of maternal blood sample. cfDNA in the maternal blood is then analyzed with next generation sequencing technology and bioinformatics pipelines to screen for any chromosomal abnormality in the fetus. If any abnormality is present, small excesses or deficits in counts of the affected chromosome can be detected.
The technology behind NIPT allows for highly accurate results with detection rates for the three most common trisomy conditions present at birth (Down Syndrome, Edwards Syndrome and Patau Syndrome) of over 99.5%. But it’s important to understand that non-invasive prenatal tests are classified as screening tests. This means that they do not test with 100% accuracy, as with an invasive diagnostic procedure such as amniocentesis.
The slides below illustrates the technology behind NIPT service offered through Groken Bioscience: