Clinical Study of Non-Invasive Prenatal Testing Using Next-Generation Sequencing

ABSTRACT

BACKGROUND: Serological prenatal screening tests are widely used to detect fetal chromosomal abnormalities such as Down and Edward syndromes. After determining the presence of fetal cell-free DNA in maternal blood, the non-invasive prenatal test (NIPT) coupled with next-generation sequencing has been performed in other countries, therefore, we developed a domestic NIPT technology. METHODS: The results of genomics-based NIPT performed between April and May, 2015 were analyzed. Maternal blood samples were collected in a specific Cell-Free DNA BCT tube. The samples were then massively sequenced using MiSeq and NextSeq 500 (Illumina Inc., USA) using LabGenomics laboratory-developed libraries. Chromosomal abnormalities were analyzed using a bioinfomatics algorithm. RESULTS: A total of 464 cases were analyzed. The samples of 12 subjects had to be collected again because of a low fetal DNA fraction in the initially obtained samples. Among the 456 cases for which fetal genome results were obtained, 436 had a low risk of trisomy, 12 had a high risk for Down syndrome, two had a high risk for Edward syndrome, and four had sex chromosomal aneuploidy, showing that the positive percentage of chromosomal abnormalities was 4.4%. All 12 cases with high risk for Down syndrome were confirmed as having trisomy 21 by amniocentesis. CONCLUSIONS: Our laboratory-developed genomics-based NIPT showed high positive predictive value, therefore, NIPT may be replaced by our own developed method.