New blood test detects genetic disorders in fetuses

Researchers at the University of Tel Aviv have developed a new blood test for genetic disorders that could allow parents to learn about their baby's health as early as 11 weeks of pregnancy.

The simple blood test allows doctors to diagnose genetic disorders in the fetus early in pregnancy by sequencing small amounts of DNA in the blood of the mother and father. A computer algorithm exploiting the sequencing results would then produce a fetal genome map, predicting mutations with 99% or greater accuracy, depending on the type of mutation.

Professor Noam Shomron of the UAA School of Medicine led the research, which was led by TAU graduate student Tom Rabinowitz with Avital Polsky, Artem Danilevsky, Guy Shapira and Chen Raff, all from the professor's laboratory. Shomron. The study is a collaboration with Dr. David Golan of the Technion-Israel Institute of Technology and Professors Lina Basel-Salmon and Reut Tomashov-Matar of the Rabin Medical Center. It was published on February 20 in the journal Genome research.

"Non-invasive prenatal tests are already available for chromosomal diseases such as Down syndrome," says Shomron. "Our new procedure is based on fragments of fetal DNA that circulate freely in the maternal blood and presents minimal risk to the mother and fetus compared to invasive techniques such as fluid testing. amniotic We will now be able to identify many mutations and diseases in a simple and safe procedure available from the doctor.

"The genetic mechanism behind Down Syndrome affects a very large part of the genome and is therefore easier to detect," says Professor Shomron. "We performed an improved non-invasive fetal genotyping, using a new and improved algorithm, to detect many other diseases caused by smaller parts of the genome – it's like looking at a map of the world and seeing not only that a continent missing, but also that only one house has disappeared.

"The practical applications are endless: a single blood test to detect a wide range of genetic diseases, such as Tay-Sachs disease, cystic fibrosis and many others."

Professor Shomron and his colleagues tested blood samples from three families at Rabin Medical Center during the eleventh week of gestation. They extracted maternal and paternal DNA from their white blood cells and fetal DNA from a sample of placental cells. They also extracted fetal DNA without circulating cells of maternal blood.

"We have sequenced all of these DNA samples and created a computer algorithm that uses parental DNA as well as cell-free fetal DNA to reconstruct the fetal genome and predict mutations," says the author. Professor Shomron. "We have compared our predictions to true fetal placental DNA, our model is the first to predict small hereditary insertions and deletions.The described method can serve as a general framework for non-invasive prenatal diagnoses."

The researchers are working to further improve the accuracy of the method and expand it to detect even more types of mutations.