General Description

Fucosidosis is caused by the lack of the enzyme alpha-fucosidase.

There are two different types of fucosidosis. They are characterized by the age of onset and type of physical and mental manifestations.

In the past, researchers described two types of this condition based on symptoms and age of onset, but current opinion is that the two types are actually a single disorder with signs and symptoms that range in severity.

For further information read the ‘fact sheet’.


Type I usually presents in the first 3–18 months of life with features typical of lysosomal storage diseases including coarsening of facial features, large liver, spleen and/or heart and dysostosis multiplex (abnormal bone formation that is found in multiple bones of the body) seen on x-ray. Cherry red spots may be present on ophthalmology evaluation. Cherry red spots are spots on the retina that have storage of sugar chains, causing the remainder of the healthy retina to look brighter. Mental retardation and seizures are also present. Additionally, sweat chloride may be elevated.


Type II fucosidosis presents between 12 and 24 months of life. Individuals usually have mild coarsening of facial features, dysostosis multiplex, mental retardation enlarged liver, spleen and/or heart involvement. In addition, angiokeratomas (superficial blood vessel dilation over which wart like growths occur) may be present. Another feature of type II fucosidosis is the presence of twisted blood vessels within the membrane covering of the eyeball and inner eyelid.

Fucosidosis is a very rare lysosomal storage disease and though the incidence worldwide is not known with any certainty, it is estimated to affect less than 1:2,000,000.

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, including Fucosidosis, 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.

Medical and Research information

  • GeneTests: A list of labs testing for Fucosidosis.
  • Genetic Home Reference: This has an excellent description of Fucosidosis with good references to other information and resources.
  • OMIM: Technical information about the genetics of Fucosidosis. OMIM is a site developed for scientists and medical specialists and contains both general and highly technical information. Access to this site is free.
  • Orphanet: A database dedicated to information on rare diseases and orphan drugs. Access is free of charge.
  • Clinicial Trials. A registry of federally and privately supported clinical trials conducted in the United States and around the world. This site gives information about each trial’s purpose, who may participate and the location.

Patient Support Groups

  • ISMRD is the international advocate for Glycoprotein Storage Diseases
  • • ISMRD’s Facebook page; this is a closed group for families only
  • • ISMRD’s public Facebook page.
  • UK MPS Society is the support group for MPS and related disease in the United Kingdom
  • • Other MPS societies around the world may also offer some support