Fucosidosis
Overview
Fucosidosis is one of seven identified Glycoprotein storage diseases. These inherited diseases are part of a larger group of disorders called Lysosomal storage diseases. Lysosomes are membrane-bound compartments found in the cells of the body. These compartments contain enzymes, which are responsible for the breakdown of many different oligosaccharides (long sugar chains). These sugar chains are continuously made and broken down in our bodies, and this process is necessary for appropriate mental and physical development. Each enzyme in the lysosome is responsible for a certain step in the breakdown of the sugar chains. When an enzyme is not working, it leads to the build up of the sugar chains in the lysosome. In Fucosidosis, the specific enzyme that is absent is called alpha- fucosidase. The build up of oligosaccharide sugars that is caused, is gradual and interferes with the correct function of the cell. It This build up is gradual and eventually leads to the clinical features of Fucosidosis. Features may progress in severity over time.
Symptoms
Some researchers believe there are two types of fucosidosis, while others classify it into three types. Still others believe there are not different types but rather different ways that fucosidosis may develop. If types are used, the symptoms are usually classified as: Type I (also called severe) begins in the first 3-18 months of life coarse facial features enlarged liver (hepatomegaly), spleen (splenomegaly), and/or heart (cardiomegaly) abnormal bone formation of many bones of the body (dysostosis multiplex) mental retardation seizures progressive deterioration of the brain and spinal cord increased or decreased perspiration Type II (also called moderate) begins between 1 and 2 years of age symptoms similar to Type I but milder, and progress more slowly horny or warty growths over blood vessels on the skin (angiokeratomas) Those who classify fucosidosis into three types suggest that Type I starts at 10 months, Type II at 18 months, and Type III (juvenile form) at 1-2 years old. Type I and Type II are considered severe and Type III mild.
Diagnosis
If a diagnosis of fucosidosis is suspected based on the child's physical appearance and symptoms, a special urine test will check for partially-broken-down sugars (oligosaccharides). If they are present, a blood sample or skin sample (biopsy) will be taken. In fucosidosis the blood or skin will have below-normal amounts of alpha-fucosidase in it.
Treatment
Individuals with Fucosidosis should have routine follow-up with Genetics, Neurology, Ophthalmology, and other specialists as needed. Currently, there is no cure to stop the progression of symptoms of Fucosidosis and treatment is aimed at addressing the individual problems as they arise. For some Glycoprotein diseases, bone marrow transplant has been trialed as an experimental therapy but there are no conclusive results on the long term benefits. Ask your specialist for more information on this.