Prenatal Aneuploidy Screening (PAS)

The prenatal aneuploidy screening (PAS) test is the first of its kind in South Africa, where microarray technology is employed to rapidly and accurately screen prenatal samples for abnormal chromosome numbers (aneuploidies), and large genetic deletions and/or duplications of chromosomal material. These chromosome abnormalities usually result in pregnancy failure (as they are not compatible with life), or can manifest as a genetic condition (such as Down Syndrome, Patau Syndrome, Edward Syndrome, Turner Syndrome and Klinefelter Syndrome).

PAS is a comprehensive chromosome screening tool
Prenatal chromosome testing methods currently available in South Africa typically only screen for a subset of chromosomes. These usually include chromosomes associated with viable aneuploidies (Chromosomes 13, 18 and 21 and the sex chromosomes). Using the same microarray technology that Genesis Genetics South Africa uses for PGS, we are able to offer PAS to screen all of the chromosomes in the genome of a prenatal sample. The chromosomes screened in the PAS test include the 22 autosomes (Chromosomes 1-22) and the sex chromosomes (X and Y).

PAS can be performed on any prenatal tissue
The tissues that we are able to test include amniotic fluid, chorionic villus samples (CVS), and products of conception (POCs). As POC material is often not amenable to cell culturing (which is a prerequisite for most genetic tests currently available), chromosome screening using microarray technology is particularly suitable for testing POCs, as there is no need to culture the prenatal tissue to perform the PAS microarray test.