Fucosidosis

Fucosidosis

For more information please download our Guide to Fucosidosis.

What is Fucosidosis?

Fucosidosis is a rare lysosomal storage disorder of the Oligosaccharide family of diseases and is closely related to Mucopolysaccharidoses.

Fucosidosis was first described by Dr Durand in 1966 and the enzyme responsible for the condition was first identified by Van Hoof and Hers in 1968.

Fucosidosis is an enzyme defi ciency disorder which results in defective fucosidase activity, the accumulation of lipids (fucose-rich oligosaccharides, sphingolipids and glycopeptides chains) and the absence of glycosaminoglycans (GAGs). This accumulation is responsible for many problems.

What causes this disease?

Oligosaccharides are long chains of sugar molecules used in the building of bones, cartilage, skin, tendons and many other tissues in the body. “Oligo” means a small number and “saccharide” is a general term for a sugar molecule.

In the course of normal life there is a continuous recycling process of building new Oligosaccharides and breaking down old ones. This process requires a series of special biochemical tools called enzymes.

Children and adults affected with Fucosidosis have a missing or malfunctioning enzyme. This is called alpha-L-fucosidase. Partially broken down fucose-containing chemicals remain stored in the body, build up and cause progressive damage to the cells.

Babies may show little sign of the disease but as more and more cells become damaged by accumulation of Oligosaccharides, symptoms start to appear.

Does Fucosidosis affect individuals differently?

Fucosidosis, like most MPS and related disorders, is very variable and in the past has been divided up into two types, one of which presents itself in infancy. This is referred to as Type I. When an individual has a later onset of the disease this is known as Type II or ‘Juvenile’. This is an oversimplifi cation, however as it is now recognised that these are two ends of the same disease spectrum. It is important to remember that Fucosidosis is extremely varied in its effects.

How common is Fucosidosis?

The MPS Society, which co-ordinates the European Registry for Mucopolysaccharide and related diseases, has been contacted regarding ten individuals in the United Kingdom. There are fewer than 100 cases that have been reported worldwide. It has been shown that approximately a third of those patients are of Italian origin.

How is the disease inherited?

Genes are inherited from our parents and control how tall we are as well as the colour of our eyes and skin. Some genes we inherit are “recessive” which means we carry that gene but it does not have any effect on our development. Fucosidosis is caused by a recessive gene. If an adult carrying the abnormal gene has a partner who is also a carrier, there will be a one in four chance (1:4) with every pregnancy that the foetus will inherit the defective gene from each parent and will suffer from the disease. There is a two in three chance (2:3) that unaffected brothers and sisters of those affected by Fucosidosis will be carriers. They can be reassured however that, as the disease is so rare; the chance of having a partner who is another carrier is very slight unless the individuals are of the immediate or extended family.

There is a more detailed explanation of this complex subject in the booklet on inheritance available from the MPS Society.