Mucopolysaccharidosis are a great group of monogenic hereditary diseases, resulting
violations of in the lysosomes multistep process of enzymatic catalysis of glycosaminoglycans (GAG).
Glycosaminoglycans - is complicated geterosahara which consist of polysaccharide chains consisting of residues sulfated hexosamine and glucuronic acid. Dermatan sulfate, keratan sulfate, heparan sulfate, chondroitin-6- and chondroitin-4-sulfate are glycosaminoglycans.
For the first time the disease mucopolysaccharidosis was described in 1917 Hurler. Currently, there are about 10 kinds of genetic mucopolysaccharidosis, five of which are the result of violations of activity of sulfatases, four - glycosidases and one type with a shortage develops transferase. When Mucopolysaccharidosis particles accumulate in the body, leading to the appearance of symptoms and various human pathologies.
The disease is inherited in an autosomal recessive manner.
What happens in MPS?
In the presence of the disease is the failure of lysosomal enzymes which are involved in the catabolism of glycosaminoglycans. As a result of deficiency of the enzyme in organs and tissues is an accumulation of glycosaminoglycans, which allows to classify storage disease mucopolysaccharidosis.
The accumulation of glycosaminoglycans leads to a violation of the functional state of different organs and systems, and due to the fact that the glycosaminoglycans are part of the connective tissue, one of the main symptoms of a systemic failure of mucopolysaccharidosis skeleton and a delay in physical development. This is especially pronounced when I, IV, VI mucopolysaccharidosis types.
Symptoms of mucopolysaccharidosis
Symptoms include mucopolysaccharidosis stunting, which begins at the end of the first year of a child's life. It should be noted coarse facial features, large tongue, overhanging forehead, ears and teeth deformity, hypertelorism. Deformed chest, pronounced kyphosis of the lumbar and thoracic spine. Characterized by hepatosplenomegaly, umbilical and inguinal hernias, limited mobility of the joints.
On X-ray examination can be seen "fish" vertebrae early ossification of occipital-parietal suture. The formation of ossification centers are not violated.
Neurological symptoms include mucopolysaccharidosis general motor retardation, diffuse muscle
hypotension. For different types of mucopolysaccharidosis also characterized by hearing loss and intellectual impairment.
Types of mucopolysaccharidosis
According to the severity of psychological symptoms and bone changes, as well as the rate of progression of metabolic disorders known mucopolysaccharidosis type 7:
- I Type I, also known as Hurler syndrome. Disease is characterized by rapid development. In the urine of patients revealed a high content of chondroitin sulfate and heparin sulfate in. Inherited by autoimmune recessive manner.
- Type II, or syndrome Gunter. When the disease is marked retinitis pigmentosa, deafness. The disease progresses slowly. The urine is also observed an increased content of heparin sulfate and chondroitin sulfate B, but in smaller quantities. Inherited recessive type, depends on gender.
- Type III, Sanfilippo syndrome. For this type of dementia characterized by heavy and large amounts of heparin sulfate in the urine. Autoimmune recessive inheritance.
- Type IV, or a syndrome Morkio.Otmechena substantial deformation of the skeleton, especially the chest. Unlike other types characterized by a lack of corneal clouding, reduced intelligence and coarse facial appearance.
- Type V syndrome Sheye. It is characterized by clouding of the cornea and moderately severe skeletal deformities. Inherited by autoimmune recessive manner.
- Type VI or Maroteaux-Lamy syndrome. Characterized by growth retardation, barrel chest, coarse facial features.
- VII type, arising from a lack of beta-glucuronidase.
Diagnosis of mucopolysaccharidosis
Diagnosis of the disease was based on a genealogical, clinical and biochemical studies.
Treatment of mucopolysaccharidosis
The disease is mainly symptomatic treatment. The patient is prescribed hormonal drugs: prednisolone, thyroidin, for suppression of ACTH mucopolysaccharides. In the treatment of mucopolysaccharidosis patients prescribed high dosages of vitamin A and medicines to normalize cardiac activity. If necessary, may appoint a cytostatic agent.
Specific prevention of disease exists. Necessary to carry out prenatal diagnosis to detect a lack of enzymes in the amniotic cells.