KU Leuven team develops test for range of genetic disorders
A group of researchers at the University of Leuven has not only developed a method to screen in vitro embryos for a range of genetic problems, it also made a breakthrough in the non-invasive testing of foetuses in utero
More reliable results
Pre-implantation genetic diagnosis (PGD) involves testing IVF embryos before they are implanted in the mother-to-be. The embryos, created in the laboratory from ova and sperm cells, are screened for genetic disorders so that only those most likely to be healthy are implanted.
The technique has mainly been used to identify one specific disorder at a time – for example in families where there is a chance of inheriting Huntington’s disease – because each disorder involves a different test.
The new test allows researchers to detect a range of disorders at once, as well as a number of more complex conditions that currently cannot be detected by PGD. The results are also more reliable than before, according to comparison studies. “The test detects chromosomal disorders in the embryo, such as Trisomy 21 [which causes Down's Syndrome], and that can improve the quality of the embryos,” explains professor Voet.
The team published its findings in the latest issue of The American Journal of Human Genetics. The group was also awarded a prize for the most promising research project at the annual conference of the American Society of Human Genetics.
Mothers’ cancer detected
The Leuven team has also made a breakthrough in the non-invasive testing of foetuses in utero – tests carried out in cases not involving IVF. In those cases, tests are done on blood samples taken from the mother, which contains the foetus’ DNA.
During pregnancy, cancer-related symptoms may well be masked
The team’s goal was to improve the accuracy of the test, as well as its sensitivity to a wider range of foetal abnormalities. However, the researchers also discovered genetic abnormalities in three cases that could not be linked to the foetuses. The abnormalities appeared similar to those found in cancer, and the women were referred for further tests.
In all three cases, doctors found early stage cancer – ovarian and two forms of lymphoma – which in all likelihood would not have been detected until much later by more conventional methods.
“During pregnancy, cancer-related symptoms may well be masked; fatigue, nausea, abdominal pain and vaginal blood loss are easily interpretable as a normal part of being pregnant,” explained professor Vermeesch. “Non-invasive prenatal testing offers an opportunity for the accurate screening of high-risk women for cancer, allowing us to overcome the challenge of early diagnosis in pregnant women.”
The researchers presented their findings to a meeting of the European Society of Human Genetics in Glasgow last weekend.