Aurora magazine

Hereditary hemorrhagic telangiectasia or HHT, from the English abbreviation, is an inherited genetic disease. It affects about 1 in 10,000 individuals and affects mainly blood vessels. Unfortunately the diagnosis is often difficult, due to the variety of symptoms.

The disease affects only a small part of the blood vessels, but with devastating consequences. Defective arteries enter the venous circuit directly, without capillaries acting as intermediaries. The pressure of the arterial blood is therefore excessive for the vein walls, which are gradually damaged. In the long run they break, causing a hemorrhage that can affect tissues or mucous membranes.

Hereditary hemorrhagic telangiectasia mainly affects skin, mucous membranes of the nose and mouth, stomach, intestine, liver, lungs and brain. Depending on the veins affected, the disease can manifest itself in different ways. The most obvious symptom is bleeding, but bleeding is not always visible from the outside. In some cases, the veins form fistulas that rarely bleed and are therefore more difficult to detect.

Each patient has different symptoms, which makes the diagnosis difficult. We are working on a genetic test, but today the diagnosis is mainly based on clinical observations. The criteria used are:

• Recurrent nose blood;
• Dilation of blood vessels on the lips, in the oral cavity and in the nose;
• Fistulas in internal organs;
• Familiarity.

For the moment it is not possible to avoid vascular lesions, so there is no definitive therapy. However, it is possible to cure most vascular lesions. As for epistaxis, they are largely avoidable with a good humidification of the domestic environment.

Source: hht.it

Charcot-Marie-Tooth disease (CMT) is a genetic disease that affects about one person every 2,500. It affects the nerves and causes weakness and muscular atrophy, which start from the feet and spread upwards. In many cases it also causes skeletal deformations that result in more or less pronounced disability. The first symptoms usually appear before the age of 20, to date many forms have been recorded.

The researchers found about 90 genes linked to the disease, but some say they could be even more. In order for the most common forms of Charcot-Marie-Tooth disease to occur, it is enough for the child to inherit even just one altered copy of the gene. However, there are forms with an autosomal recessive and other modalities related to the transmission of the X chromosome. In the latter case, women suffer from a milder form than men.

For the diagnosis of Charcot-Marie-Tooth disease one always starts from clinical observation, supported by an electromyographic examination. Where necessary, nerve biopsy is also used. Genetic tests make the diagnosis more reliable and help prevent transmission to children.

The great genetic variability of the disease makes the treatment difficult. Several studies are underway to evaluate possible treatments. One of the most promising concerns the administration of ascorbic acid in patients with mutations in the PMP22 gene. However, years of further study will be required. For the moment, therefore, it mainly acts through physiotherapy and orthopedic surgery.

Source: telethon.it

Krabbe disease is a rare and fatal genetic disease. It affects the insulating surface that covers the nerve fibers, myelin, causing serious neurological damage. The most common form (about 90% of cases) occurs within 6 months of age and leads to death within 3 years.

There is also a less common form, which occurs in adolescence or even adulthood. The symptoms manifest themselves progressively. Children are irritable and hypersensitive to sounds. They begin to suffer from recurrent fevers even without infections, accompanied by vomiting and weight loss.

The little ones stop developing, become rigid and begin to regress. As the disease progresses, they lose the ability to move voluntarily. In the last stages they become blind and deaf. Krabbe disease is thought to be linked to alterations in the GALC gene, which encodes the enzyme galactocerebrosidase.

When the enzyme is missing, some substances toxic to the cells start to accumulate in the brain. As they accumulate, myelin deteriorates and causes all the symptoms seen above. Unfortunately, the mechanism is not yet completely clear.

The disease is transmitted in an autosomal recessive manner: both parents must be healthy carriers, so that it manifests itself. Diagnosis is made through clinical observations and instrumental investigations, such as MRI. To confirm it, enzymatic and DNA tests are used. If a couple had already had a child with the disease, they can use prenatal diagnosis.

Source: telethon.it

Prader-Willi syndrome is a genetic disease that occurs at birth and can take many forms. The disease is in fact linked to a large number of genetic variants, which cause very different symptoms.

The first symptom is the severe lack of muscle tone present since birth, which makes swallowing difficult. From the age of two, symptoms related to behavior and learning begin to appear. The child is never satiated, which in the long run can lead to severe obesity. Moreover, he has learning difficulties and obsessive-compulsive behaviors. Sometimes, symptoms similar to those of the autistic spectrum occur.

Those suffering from Prader-Willi syndrome tend to have peculiar facial features:

• narrow forehead;
• almond eyes;
• mouth turned downwards;
• scoliosis;
• thin upper lip;
• small hands and feet;
• short.

The syndrome is caused by genetic abnormalities concentrated on chromosome 15 inherited from the father. The maternal genes present in this area are not active, so the paternal anomalies are enough for the disease to manifest. Familial cases are rare: more often than not, Prader-Willi syndrome occurs due to sporadic anomalies.

The diagnosis always starts from clinical observation and genetic analysis is used to confirm it. For couples who have already had a child with the disease, prenatal diagnosis is possible.

Source: telethon.it