Symptoms of Mucopolysaccharidosis

Symptoms of Mucopolysaccharidosis vary and include diarrhoea, abdominal pain, swelling, and muscle weakness. Some people are able to treat the condition with medication, while others have to undergo surgery to correct the disorder. It is important to understand the disease and how it can affect you so that you can take the right steps to get the care you need.

Diagnosis

Several studies have shown that the diagnosis of mucopolysaccharidosis is not always straightforward. As the condition is a heterogeneous group of disorders that are clinically similar, it can be difficult to distinguish them. A multisystem disease, it can cause a wide array of symptoms including skeletal malformations, ocular abnormalities, joint contractures, and pulmonary dysfunction.

The first and most important step in the diagnosis of MPS is to identify the lysosomal enzyme deficient form. This can be done by using specific enzyme assays. Usually, this is performed in blood. However, plasma or leukocytes are not appropriate for this test.

The second step involves the use of electrophoresis to separate macromolecules on a charge basis. Similarly, tandem mass spectrometry can be used to demonstrate the functional impact of the deficient enzyme.

Symptoms

Symptoms of mucopolysaccharidosis vary from patient to patient, but in general, it is characterized by skeletal abnormalities and intracellular accumulation of glycosaminoglycans or GAGs. This buildup results in a restricted range of motion in joints, stunted growth, and decreased mobility. Eventually, cellular damage leads to organ failure.

The aforementioned enzymatic replacement therapy (ERT) is the mainstay of treatment for severe MPS 1. Other enzymatic treatments include immunosuppressive agents,  stem cell transplantation, and genetically modified idursulfase, which is available in Japan since 2007. In a nutshell, ERT prevents permanent tissue damage from substrate deposition. The benefits of ERT are a decrease in somatic signs and symptoms, improved quality of life, and an increased sense of well-being.

Causes

Symptoms of mucopolysaccharidosis vary from mild to severe, depending on the subtype. The condition is characterized by an accumulation of complex carbohydrates in the body. This can damage the joints and bones. It can also cause intellectual disability.

The disorder is caused by a genetic defect. It occurs when there is a deficiency in one of the lysosomal hydrolases. The enzymes are responsible for breaking down fats and other molecules. They are highly specialized proteins. Without enzymes, the body accumulates different types of complex carbohydrates. The build-up can damage the brain and bones, leading to pain and other symptoms.

It is rare, with about one in 25,000 babies born with the disorder. The symptoms can develop in the first year of life. It can lead to problems with the respiratory system and the heart. Some cases may require heart valve replacement. It can also result in a build-up of nerve root compression in the spinal cord.

Treatment

Various clinical-stage biopharmaceutical companies have pipeline candidates for new therapeutics. Emerging therapies, such as enzyme enhancement therapy, substrate reduction therapy and gene therapy, are in development. In addition, several pharma companies are also developing drugs for rare diseases. This will fuel the mucopolysaccharidosis treatment market demand.

Mucopolysaccharidosis treatment involves continuous treatment plans. This helps to slow the progression of the disease. Although the disease has no known cure, a few treatment centres are helping to improve the condition. It is often detected at an early age, which helps to prevent the development of more severe symptoms.

The disease can lead to complications such as cardiac problems and vocal infections. In addition, the disease can cause other health concerns, such as abnormal bone structure, enlarged vocal cords, joint deformities and many respiratory infections.

Mortquio syndrome

Described in 1919 by Luis Morquio, Morquio syndrome is a mucopolysaccharidosis. This disorder occurs in people who have two copies of a gene with mutations. It is a multisystem disease affecting the skeletal, respiratory, and circulatory systems. It also involves the connective tissues.

Morquio syndrome is caused by mutations in a gene called GALNS. This gene encodes the enzyme N-acetylgalactosamine-6-sulfatase. It is responsible for the degradation of keratan sulfate. Without this enzyme, keratan sulfate accumulates in the body. This accumulation causes damage to the cells. It also affects the bone and cartilage.

Patients may also have conductive hearing loss. This can occur because of a build-up of fluid behind the ear drum. A myringotomy tube may be used to treat this condition.

DiFerrante syndrome

Various symptoms can be observed in those with this rare disease. It can affect multiple organs, including the liver, lungs, and kidneys. It can also lead to life-threatening complications. It is a chronic progressive disease that causes a gradual decline in physical and mental function.

The mucopolysaccharidosis II disease is characterized by the absence of an enzyme, iduronate-2-sulfatase. This enzyme is part of the catabolism process of glycosaminoglycans. A deficiency of this enzyme leads to the accumulation of complex carbohydrates in the body, which may cause damage to organs.

X-linked mutations in the IDS gene are the primary genetic causes of MPS II. It is located in the chromosome region Xq28. This gene is 44 kb long and is structured into nine exons.

Additional info: Mucopolysaccharidosis – Wikipedia