Aurora magazine

In recent years, the non-invasive prenatal screening tests for Down's syndrome are gaining ground. According to a study by the Murdoch Children's Research Institute (MCRI), other genetic tests should be added to this widespread test.

Fetal DNA tests for prenatal diagnosis of Down syndrome are offered to all women over a certain age. In the case of other genetic diseases, however, it is thought that the problem concerns only those who have had cases in the family. Yet fragile X syndrome, spinal muscular atrophy and cystic fibrosis have a risk rate comparable to that of Down syndrome, if put together.

Genetic tests for the three hereditary genetic diseases have been available since 2012. They are usually recommended to those who already suspect they are healthy carriers. A way of acting that neglects a large part of the population, perhaps unaware of their family history. The principal author of the study, Professor David Amor, believes that these tests should be available for all couples wishing to make a child.

From the data collected it emerged that 1 in 20 people among those analyzed is the bearer of one of the three genetic diseases. 88% of these individuals were not aware of the risk, as they were not aware of any case in the family. So none of them would have carried out the genetic test, if it had not been involved in the test.

Among the couples analyzed, 1 in 240 presented a high risk of transmitting the disease to the offspring. In addition, prenatal screening tests revealed the presence of one of the diseases in about 1 pregnant woman in 1000. These are comparable to the incidence of Down syndrome.

Source: medicalxpress.com

Friedreich's ataxia is a rare genetic disease that causes progressive degeneration of the nervous system. It affects in particular the spinal cord and the cerebellum, causing the lack of coordination of the movements, the ataxia precisely. It usually occurs during childhood or adolescence, but in some cases it also appears in adulthood.

The first symptoms of Friedreich's ataxia are problems of balance and coordination. These make it difficult to write, eat and perform other very simple activities. In time, even walking becomes impossible, forcing those who suffer in a wheelchair. Cardiac problems and diabetes are also common.

The causes of Friedreich's ataxia lie in the alterations of the gene that encodes the frataxin protein. A sequence of three nucleotides of DNA is repeated many times more than normal, blocking the functions of the entire gene. This therefore causes the missing coding of the frataxin, with consequent deficit due to the symptoms of the disease.

Transmission occurs by means of an autosomal recessive mode: if both parents are carriers of a mutated copy of the gene, the child will have a 25% chance of being ill. Often neither partner knows that they are a healthy carrier, making it difficult to make a prenatal diagnosis.

Diagnosis is based on the observation of symptoms, on tests such as the electromyogram and on the genetic test. The latter serves to identify the genetic defects mentioned above. Once you have received a positive result, however, there is very little to do. To date there is no cure for the Friedreich ataxia.

Source: telethon.it

Hunter syndrome, also called Type II mucopolysaccharides, is a rare genetic disorder. According to the data, around 2,000 people with this disease would be around the world. Those who suffer from it have symptoms such as mental retardation, macrocephaly, aggression.

Hunter is a lysosomal disease, which is caused by the deficiency of an enzyme. Specifically, subjects suffer from an L-iduronate-2-sulphatase (I2S) enzyme deficiency. This is due to the catabolism of mucopolysaccharides or GAG. When absent, the substances accumulate in the cells and lead to a progressive deterioration of heart, liver, spleen, bones and brain.

Depending on the severity, Hunter's syndrome is distinct in Form A and Form B. Form A is the most serious and premature, so it usually leads to death within the fifteenth year of life. In many respects it is similar to another illness involving mucopolysaccharides, Huler's disease. Those who suffer from Form A have gross features and bony deformities. It is often of low stature, showing muscle rigidity and mental retardation.

Most of the time, type A Hunter syndrome shows up to 2-4 years. Children show progressive neurological and somatic deterioration. Over time, the symptoms evolve into chronic diarrhea and mucous dysfunction. Most patients die before adolescence

Hunter's B-form B manifests itself later and is less severe, so much so that those who suffer from it almost always come to adulthood. B is linked to carpal tunnel syndrome, joint stiffness, and cervical myelope due to narrowing of the spinal canal. Many patients show discrete corneal opacity and retinal dysfunctions, though less extensive than that of the severe form.

Source: observatoriomalattierare.it

In the future, will it be possible to correct a genetic error directly in the body? Maybe yes. The scientists at the Oakland Benioff Hospital have applied gene therapy to a man with Hunter's disease. If all goes well, the body will incorporate the correct version of the defective gene, hence a regression of the disease.

In standard gene therapy, offensive viruses are used to replace diseased genes with their correct versions. Usually, scientists apply the procedure on a cell culture of the patient, to be re-planted at a later time. In this case, instead, they used genetic editing directly in the patient's body.

Scientists have operated a man suffering from a disease called mucopolysacaridosis type 2, or Hunter's disease. Those who suffer from it accumulate sugars in the organelles of the cells, all because of a chronic scarcity of the enzyme Ids. In the long term, the accumulations of sugar cause problems of sight, hearing, heart. To date, the only available treatment is weekly enzyme infusion, but gene therapy may make it unnecessary.

Phases 1 and 2 of the experiment are intended to verify the safety of the treatment. Only at this point will you go to Stage 3, which will serve to verify its effectiveness. For this purpose, researchers have already recruited 9 other patients with the disease who will undergo short-term surgery. In addition, similar experiments are ongoing for type B hemophilia and type 1 mucopolysaccharides, or Hurler-Scheie syndrome. The criterion used is always the same.

Source: ansa.it