Fucosidosis is a rare lysosomal storage disorder[2] in which the FUCA1 gene experiences mutations that severely reduce or stop the activity of the alpha-L-fucosidase enzyme.

The gene encoding the alpha-fucosidase, FUCA 1, was found to be located to the short arm of chromosome 1p36 - p34,[4] by Carrit and co-workers, in 1982.

Other results are progressive neurological deterioration, skin abnormalities, growth retardation, skeletal disease, and coarsening of facial features.

[7] Fucosidosis is an extremely rare disorder first described in 1962 in two Italian siblings who showed progressive intellectual disability and neurological deterioration.

[12] Typically affecting dogs between 18 months and four years,[citation needed] symptoms include:[13][14] From the onset, disease progress is quick and fatal.

As in the human version, canine fucosidosis is a recessive disorder and two copies of the gene must be present, one from each parent, in order to show symptoms of the disease.