Catalan researchers have developed a technique that allows for more accurate examination of the fetus for genetic anomalies. Unfortunately, the new method is twice as expensive and still carries the risk of miscarriage.
The trial application of a new technique of prenatal testing carried out by the Catalan company qGenomics has shown that it is more accurate and faster than the methods used so far. Research carries the same risks as traditional tests, but the cost is twice as high. Probably for this reason they will not be used on a large scale for the time being, especially if we take into account the current budget cuts in the health service. Since the 70s, prenatal testing in high-risk pregnancies has been based on the collection of fetal cells and the examination of their chromosomes under a microscope. This method is effective when dealing with serious chromosomal abnormalities causing Down’s syndrome, but it cannot detect minor disorders which, however, can cause serious diseases. In an era of reading the human genome, when it is possible to study the slightest genetic abnormality, scientists at the Center for Genomic Regulation at Pompeu Fabra University (UPF) considered relying on a prenatal testing method developed more than thirty years ago to be anachronistic.
They managed to create a DNA chip to track a small genetic disorder, and then founded qGenomics to bring the new method to market. qGenomics is a good example of how modern research carried out in Catalonia can turn into a significant income. According to the Biocat 2011 report, currently the number of Catalan companies created as a result of research in the field of biotechnology, biomedicine or medical technology is already 481. Most companies, such as qGenomics, were born on the initiative of entrepreneurial scientists. They are usually small and employ fewer than twenty employees, although there are also those employing over a hundred people – a total of 22 people find jobs there. people.
The first report in which researchers at qGenomics compared their technique with the conventional method confirms that the DNA chip produces more accurate results. According to a report published in the Human Genetics magazine, classical chromosome analysis detected 42 genetic diseases among the 900 high-risk pregnancies studied, while the DNA chip found 56 of them. detected with currently used methods – emphasizes Lluís Armengol, director of qGenomics and the main author of the report. It is worth explaining that a genetic disorder of at least five million base (letter) pairs can be detected by classical chromosome testing. By comparison, a qGenomics chip can pick up a hundred times smaller anomalies (about 1,6 DNA bases).
According to the director of Armengol, the new test can detect over 150 different disorders. The examined women were patients of two hospitals: Vall d’Hebron in Barcelona and La Paz in Madrid. All of them required prenatal testing, be it because of their age, or family history of hereditary conditions or ultrasound abnormalities. Among the fourteen genetic disorders detected with the qGenomics chip were abnormal brain structure, severe heart defects, and other, less severe genetic disorders. After talking to a specialist who explained the test results and the impact of the possible disease on the child’s life, six couples decided to have an abortion, and eight decided to have a child.
Another advantage of the DNA chip is that the test results can be picked up after just three days, while the traditional chromosome test result takes three to four weeks. “This is a significant difference for couples who are waiting for the results to be able to decide whether to continue the pregnancy or have an abortion,” emphasizes Armengol. It is worth noting, however, that the test based on the qGenomics method is almost twice as expensive as the chromosome analysis. Once in common use, its price will certainly drop, but now it costs over 400 euros to conduct the study.
The new method is based on the analysis of fetal cells, taken mostly from amniocentesis from amniocentesis, and sometimes from the outer membrane of the placenta. It is therefore the same technique used for chromosome analysis and carries the same risks to the fetus. It is estimated that the collection of fetal cells is associated with 0,5 percent. risk of miscarriage – one pregnancy in 200 – which explains why prenatal tests are performed only in pregnancies with a high risk of serious disorders in the child. Currently, the biggest challenge for qGenomics is to bring its method to the market in such a way that it becomes widely available quickly. The test can also be performed after the baby is born to determine the risk of genetic diseases and, according to Armengol, private health services already use it in these cases. The director admits, however, that now “you need to familiarize yourself with this method of gynecologists in order to popularize a new technique of prenatal examinations”.
Future challenge: mother’s blood test
During pregnancy, a small number of the fetal cells pass into the pregnant woman’s blood. If a fetus has any genetic abnormalities, it should theoretically be possible to detect them by analyzing the cells in the mother’s blood. Once this is established, “it will be possible to perform prenatal testing without risking a miscarriage,” explains Xavier Estivill, geneticist at the Center for Genomic Regulation and founder of qGenomics.
Such tests can be performed for all pregnancies, even if the disease is not suspected. As Estivill argues, this is “the future and the direction in which science is heading”. For now, however, scientists do not know a large-scale method of extracting fetal cells from the mother’s blood.
Text: Josep Corbella