01

About the test

Other prenatal tests are available after mid pregnant and its accurate rate is lower. Also, diagnostic tests such as amniocentesis and chorionic villus sampling are invasive method and have the risk of miscarriage. For this, many feel afraid.
On the other hand, NICE® is safe using maternal blood without the risk of miscarriage or rupture of membrane caused by invasive prenatal test and accurate with over 99% detection rate.

04

How is the NICE® performed

NICE® looks at isolated fetal cfDNA present in maternal blood, collected after 10 weeks of pregnancy from massively parallel WGS. Sequencing data is analyzed by applying the bioinformatics pipeline.
After removing the GC bias, normalized reads are used for further analysis. The size selection method is used to separate and analyze fetal-derived cfDNA and maternal-derived cfDNA according to the size distribution of cfDNA. To detect chromosomal aneuploidies, we use a multi-Z method with 21 z-scores for each autosomal chromosome. First, fetal sex is determined using Y-derived reads, and the fetal fraction is analyzed using sex-specific bioinformatics pipelines.

04-1 Pre-processing (Sequencing)

Figure 1. outlines the bioinformatics process from maternal blood collection to reporting of test results.

04-2 Size selection method

04-3 Bioinformatics anslysis

Figure 2. The workflow of Nice® pipeline based on size selection method using cfDNA fragment size.

05

Why NICE® is different

If there is an abnormality in the chromosomes derived from the placenta or the mother, false negatives and false positives may appear as a result of NIPT. Although the proportion of false- negative and false-positive results in NIPT are very small, the reporting of false results cannot be ignored in clinical setting.

Table1. Differences between NICE® and targeted sequencing methods

Multi-Z method

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  The multi-Z method has the advantage of being more precise by using a 21 z-scores compared to the existing methods using one or two z-score thresholds by other labs.

• Size selection method

  The bioinformatics pipeline of the NICE test aimed to improve the accuracy of NIPT by dividing and analyzing fetal or maternal cfDNA based on cfDNA size differences. Through the size selection method, fetal-derived cfDNA analysis had the effect of increasing the fetal DNA fraction, and maternal-derived cfDNA analysis had the effect of removing factors affecting maternal chromosomal abnormalities and increased NIPT accuracy. In addition, when gDNA is contaminated, the distribution of cfDNA fragments is different, so the quality of sequencing data is controlled through the distribution of cfDNA.

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01 XO Case : Not detected (Maternal Mosaicism)

02 Trisomy 18 : 2-step confirmation