Aurora magazine

The fragile or Martin-Bell X syndrome is a genetic disorder that causes mental retardation and mild dimorphism. The cause is a mutation of the FMR1 gene on the X chromosome, affecting 1 child in 1250 and 1 child in 2500.

At the base of the disease there is a dynamic mutation that causes a deficiency of the FMRP protein. Under normal conditions, the affected DNA tract has between 6 and 50 copies of CGG triplets. In healthy carriers, copies are 50-200. In the diseased subjects, instead, this stretch of DNA expands progressively and leads to the aforementioned deficit.

In healthy subjects, the FMRP protein binds with RNA. It is found mainly in the testicles and the brain, which is why these are the organs most affected by his absence. The deficiency manifests itself gradually, in a period between the first months of life and puberty. Symptoms are varied and often not easy to identify. In some cases they are also linked to other diseases, delaying the diagnosis.

The most obvious physical symptoms are elongated face, low-planted auricles, protruding jaw. In some cases, strabismus and dental occlusions are also present. Some patients with fragile X syndrome also suffer from macrocephaly and mitral valve prolapse. In the post-pubertal phase, an increase in the volume of the testes can also occur.

Fragile X syndrome is the most common cause of inherited mental retardation. The extent of the delay, however, is variable and accompanied by other symptoms. Those suffering from Martin-Bell often show hyperactivity, attention deficit, autistic behaviors and emotional instability.
Given the wide variety of symptoms, the diagnosis can be difficult. We often get there by exclusion, or by examining similar cases in the family. In the latter case, it is also possible to resort to prenatal diagnosis.

Source: osservatoriomalattierare.it

Magnetic resonance imaging (MRI) has unveiled new details on fragile X syndrome. The white matter of the children who suffer from it is less developed than the average. The next step will be to study white matter from different angles, to focus on the brain circuits involved in communication between neurons.

The study by UNC School of Medicine researchers showed that brain differences predate the diagnosis of the disease. Usually the fragile X syndrome is detected around 3 years, if not later. However, brain damage is much earlier. With the right analysis, therefore, it would be possible to diagnose the disease much earlier. It would also avoid the many wrong diagnoses related to the disease.

Unfortunately, in this case early diagnosis is not synonymous with early treatment. For the time being there are no treatments for fragile X syndrome. However, the discovery could facilitate research. In fact, the differences detected in the white matter could become the basis for new studies.

The study involved 27 children with fragile X syndrome and 73 healthy children. Researchers collected images made with magnetic resonance imaging. In particular, they focused on 19 bundles of myelinated axons, ie the longest arms of neurons. These connect the various parts of the brain to each other, allowing rapid communication between neurons. A good connection between neurons is essential for the proper functioning of the brain, especially in the age of development.

Children with the syndrome showed abnormalities in the development of beams 12 and 19 from 6 months of age. These newborns had much less developed fibers in various parts of the brain, although the symptoms were not yet evident.

Magnetic resonance images confirmed previous observations made on mice. In particular, it emerged as the expression of the X fragile impacts on development from the beginning. A promising revelation, which could facilitate the discovery of new early treatments.

Source: med.unc.edu

Under the term "mitochondrial diseases" include disorders with heterogeneous characteristics. In general, it indicates a group of inherited genetic diseases caused by mitochondria malfunction. The latter are the "energy centers" of the cells. When they do not work properly, they cause disturbances that can involve different tissues.

Mitochondria have their own DNA, susceptible to alterations other than that of nucleotide DNA. Mitochondrial diseases are the result of these alterations and are hereditary, even if they follow their rules. At the time of fertilization, the new individual inherits the mitochondria only from the egg cell. For this reason, diseases of this type are often inherited only by the mother.

Most mitochondrial diseases affect the muscles and the brain. In fact, it is the tissues that most need energy and therefore suffer the most from it. Usually these two forms of mitochondial diseases occur with anemia, pancreatic dysfunctions and cardiac disorders. Often the children who suffer from it show slow growth, deafness and diabetes. Adults tend to get tired soon.

Heterogeneity of symptoms makes diagnosis of mitochondrial diseases difficult. Usually the suspicion arises from the presence of symptoms with progressive course in unrelated organs. The definitive diagnosis comes by finding the deficiency of certain proteins, essential for producing energy. In recent years, the use of genetic tests and prenatal screening tests has also spread. The latter are useful in the presence of family cases.

To date there is no cure for mitochondrial diseases. In some cases it is possible to make up for the deficit of certain substances. There are also medicines useful for reducing the most debilitating symptoms and slowing the progression of the disease.

Source: telethon.it

Gardner's syndrome is a genetic disease characterized by intestinal polyps and benign tumors in the colon-rectum. The disease is caused by mutations in the Adenomatous Polyposis Coli (APC) gene. APC encodes proteins that control cell division and their development. The mutation triggers an uncontrolled cell growth, which results in the formation of polyps and tumors.

Gardner's syndrome is a rare disease and affects approximately 1 in 1,000,000 people in the United States. In order for it to occur, it is enough to inherit only one copy of the faulty gene, but it is not always hereditary. On the contrary, the disease tends to appear much more often due to sporadic genetic mutations.

Symptoms of the syndrome can also change a lot from patient to patient. The main feature is the presence of polyps in the colon, which affects about 80% of patients. The other possible symptoms are:

• Polyps in the stomach
• Dental abnormalities
• Tumors of benign bones
• Tumors of the skin and benign connective tissues
• Congenital hypertrophy of retinal pigment epithelium.

Gardner's syndrome can be identified by a simple genetic test, which identifies the mutation in APC. If there are cases in the family, it is recommended to take the test before having children. In addition to genetic testing, the other diagnostic tools are colonoscopy and ultrasound. Retinal lesions and abnormalities in the skin can also indicate the presence of the disease.

Usually the syndrome occurs around the age of 16, but there are cases even around 10 years. If left untreated, Gardner's syndrome leads to the development of malignant tumors around the age of 40. For this reason, those suffering from it perform annual screening. In the case of multiple and aggressive polyps, it is even recommended to remove part of the colon.

Source: news-medical.net