Non-invasive prenatal testing of the most common chromosomal aberrations (NIPT)

Non-invasive prenatal testing of the most common chromosomal abnormalities of the fetus from blood of a pregnant women (NIPT)

 

1. Clarigo non-invasive test

From January 2016, our centre performs non-invasive prenatal testing of the most common chromosomal aberrations (NIPT) – CLARIGO v2 test – CE-IVD kit by Multiplicom (Agilent Technologies). The sequencing is performed by Illumina sequencing technology – NGS System MiSeq.

This test is indicated to patients according to the Recommended Procedure of the Society of Medical Genetics and Genomics of the Czech Medical Society of J. E. Purkyne as an alternative to amniocentesis or chorionic villus sampling and for selected patients at risk.

Clarigo NIPT is an advanced non-invasive test for detection of chromosomal aneuploidies (chromosomes 13, 18 and 21), and sex determination from maternal blood (analysis of cell‑free fetal DNA in maternal blood). The test can determine the risk for aneuploidies of sex chromosomes. Determining the risk of sex chromosome defects does not preclude the possibility of sex chromosome abnormalities in the fetus as this part of the test is not validated yet. A patient receives detailed information that this test can detect aneuploidy of the above chromosomes – it is neither examination of the whole fetal caryotype, nor examination of microduplication and microdeletion syndromes.

In 1-3% of cases, it is not possible to determine the result of the test and the collection of maternal blood must be repeated, or e.g. amniocentesis is performed.

The detection rate of this test is more than 99% for Down syndrome, more than 99% for Edwards syndrome, and more than 99% for Patau syndrome. Therefore, a very low risk of false-negative test result cannot be excluded, 100% detection of these syndromes by non-invasive testing is not yet possible. In the case of positive result of non-invasive testing, it is necessary to verify the result by an invasive procedure.

In medical terms, invasive testing (chorionic villus sampling or amniocentesis) is appropriate in pathological ultrasound finding (higher NT, congenital malformations of the fetus etc.). Furthermore, in case of risk of the integrated test higher than 1:50, it is also preferable to perform invasive examination including a detailed Array CGH analysis of the fetus (covering tens of rare genetic diseases).

 

Non-invasive testing (NIPT) at the patient’s request without medical indication can be performed for direct payment from gestation week 10+3; detailed ultrasound examinations in gestation weeks 13 and 20 are very important. 

 

2. MaterniT21 PLUS, MaterniT GENOME

 

Our centre performs non-invasive prenatal testing of the most common chromosomal aberrations (NIPT) MaterniT21 PLUS and MaterniT Genome. Blood sampling is performed after regular ultrasound examination and genetic consultation. In case of positive test result, it is necessary to verify the result by an invasive procedure. We would like to inform you about the technical and practical aspects of the MaterniT tests. These laboratory tests are carried out in Sequenom Laboratories, San Diego, USA. Czech partner for sample preparation and transport is Vaše laboratoře s.r.o., Zlín, CZ.

More information here