8 November 2021
A KAIMRC laboratory is the first in Saudi Arabia to offer prenatal and pre-implantation screening tests for chromosome abnormalities. The genetic resource will help women who are pregnant or those struggling with infertility to make more informed choices about their family planning in ways that are safe, accurate and minimally invasive.
“Our main goal is really to help more families have healthy children,” says KAIMRC deputy executive director Majid Alfadhel, the pediatric geneticist who heads the lab.
Alfadhel and his colleagues outlined their experience implementing the diagnostic service in two reports published this year. In both papers, the researchers focused on detecting an abnormal number of chromosomes, a condition known as aneuploidy that can reduce fertility by causing miscarriages and may also result in neurodevelopmental disorders in babies. However, each study aimed to detect aneuploidy in a different clinical context.
The first centred around testing in vitro fertilization (IVF)-created embryos before they are implanted in the uterus1, a process known as pre-implantation genetic testing for aneuploidy (PGT-A). In the second, researchers analysed foetal DNA found in blood samples from pregnant women2, a method known as non-invasive prenatal testing (NIPT). The KAIMRC team began offering both diagnostic services in late 2019 in partnership with Department of Pathology and Laboratory Medicine at King Abdulaziz Medical City in Riyadh.
The researchers carried out PGT-A tests on embryos created for 36 Saudi couples who had either experienced prolonged infertility or had had trouble getting IVF-generated embryos to implant successfully. The majority of the 200 embryos tested were not deemed suitable for transfer—120 had chromosome anomalies and 34 were of low quality overall. However, 46 embryos with normal chromosome counts were recommended for transfer, and many yielded successful pregnancies.
“It’s a good tool for improving implantation rates,” says Yusra Alyafee, team leader for prenatal and pre-implantation screening at KAIMRC and the first author of the two new reports.
The researchers were similarly successful with NIPT. Of the first 200 tests run, 13 revealed a high risk for aneuploidy, only one of which later proved to be a false positive when examined with more invasive screening techniques. All 187 negative tests accurately foretold the birth of healthy babies without chromosome defects.
The lab has since performed around 1,000 NIPT tests for Saudi women. As Abeer Al Tuwaijri, a co-author on the new studies, points out: “It’s getting more popular over time.”
- Alyafee, Y. et al. Next-generation sequencing-based pre-implantation genetic testing for aneuploidy (PGT-A): First report from Saudi Arabia. Genes 12, 461 (2021). | article
- Alyafee, Y. et al. Next generation sequencing based non-invasive prenatal testing (NIPT): First report from Saudi Arabia. Frontiers in Genetics 12, 630787 (2021). | article