Aurora magazine

A team of Estonian scientists has announced that they have found a way to make genetic tests more precise. The new technology makes it possible to analyze the number of clinical biomarkers at the molecular level. This should increase the accuracy of the tests, making them even cheaper. If the TAC-seq method proved to be reliable, it could be used both for the diagnosis of genetic diseases and in fertility clinics.

The method measures the number of DNA and RNA molecules used as biomarkers and present in the samples. In this way it gives a more accurate picture of the patient's health status. It indicates the presence of illness, but also the possible reactions to certain drugs. Among the possible applications, there is the identification of the best period to implant an embryo.

Traditional genetic tests amplify DNA, otherwise there is not enough material for sequencing. Unfortunately it is not known how many copies of the original molecule are, so the results are necessarily less accurate. The new method, on the other hand, identifies and removes all copies of the original molecule. In this way the results are much clearer and reflect the real conditions of the patient.

For the moment there are three possible applications for the method.

• Endometrial receptivity test. It could help to determine the levels of specific RNA molecules, so as to identify the best time to implant an embryo.
• Non-invasive prenatal screening. In the future, it could improve the fetal DNA tests available today.
• Profiling of microRNA molecules. These molecules are biomarkers of different diseases and the method would save patients many biopsies.

Source: eurekalert.org

Chronic intestinal atrial dysrhythmia syndrome is a rare disease that affects the heart and the digestive system. A team of Canadian scientists has studied geology in Quebec, so as to understand where it develops the most. To do this, they used a software called ISGen that analyzed the DNA of more than 3.4 million people of European origin. In this way they found the roots of the disease in the first French immigrants, who arrived in Canada around the seventeenth century.

Beyond the historical interest of the discovery, the software has identified the regions of Quebec most subject to the disease. ISGen has simulated the different modes of transmission of the rare allele. In relation to the inheritance patterns of alleles, he considered the possible genotypes present in the database. Furthermore, he took into account the frequency of ancestral alleles and observed the genotypes of certain individuals within the genealogy.

Overall, the researchers analyzed genealogical data of about 3.4 million individuals, spread over 17 generations. Geographic information was also available for 2.7 million individuals. The analyzes also used data from the genotypes obtained from a regional project, obtained using the Illumina technology. Thanks to this approach, they traced the allele responsible for the disease.

The scientists followed the path of the offending allele, arriving at two original families. The first carriers of the disease were no more than 5. Today in Quebec the syndrome of chronic intestinal atrial dysrhythmia manifests itself in an individual every 24,025. According to the authors of the study, it is therefore important to concentrate genetic screening in this area.

Source: mcgill.ca

Two twins born in September in China would be the first genetically modified human beings. This was announced by Professor He Jiankui of the University of Shenzhen, who led the experiment. The scientists used Crispr to make the twins resistant to AIDS. At the moment there are no confirmations from third parties, but the news is still exceptional. Nevertheless there are doubts, both ethical and technical.

Despite its great potential, Crispr is still an imprecise one. Several researchers have questioned the safety of the technique, which could lead to unexpected changes. For this reason, for the moment it is used only on somatic cells and never on reproductive cells. In most countries of the world it is even forbidden to modify the DNA of the embryos. China is not new to such experiments, but it is the first time that a scientist has gone so far.

Professor He Jiankui eliminated the gene that encodes the Ccr5 protein from 7-pair embryos. The protein is the receptor that carries the HIV virus inside the immune cells. Without it, the virus can not infect them and the individual is in fact immune to AIDS. After this first step, he and his team implanted embryos from one of the couples in utero. The pregnancy has progressed and has come to an end.

The experiment would fail in at least one of the twins. The researchers altered only one copy of the gene, so the child is not immune to the disease. As for the other, there are still no certain news.

Source: corriere.it

Rice University Gang Bao bioengineer has created a new genetic editing technology. To do this he combined magnetic nanoparticles with a virus coming from the moths. The technique could help fight diseases such as muscular dystrophy, cystic fibrosis and sickle cell anemia.

Magnetic fields are easy to manipulate and pass through the tissues. Dr. Bao has therefore decided to use them to control the expression of viral loads in specific tissues. The technique allows in fact to activate viruses that otherwise would remain inactive in the blood, making the therapy less effective. In this way, instead, more viruses manage to reach the target and modify more cells with the correct version of the gene.

CRISPR / Cas9 has the potential to fight most genetic diseases. There are two problems: possible side effects; be able to change as many cells as possible. So we need a way to get a good slice of the virus in the tissues of interest, but the spatial control within the body is a challenge. Even if viruses are injected locally, there is always the possibility that they will displace and dispense the therapy.

Dr. Bao's team started with a moth-like virus, cylindrical in shape and large enough to carry 80,000 strands of DNA. Enough to change the genetic code of multiple cells. Scientists have combined the virus with magnetic nanoparticles, which can make the virus pass through the walls of the blood vessels. In this way they managed to get the changes only where needed, increasing the efficiency of CRISPR / Cas9.

Source: news. rice. edu