The Molecular Basis of Canine Fucosidosis

Fucosidosis is the lysosomal storage disease resulting from a deficiency of α-L-fucosidase [EC3.2.1.51]. It has been described in children [1] and in pedigree English springer spaniels in Australia [2] and the United Kingdom [3]. Canine fucosidosis is a progressive neurological disorder with the onset of clinical signs occurring at 18-36 months, suggesting a similarity with the adult form (Type 2) of human fucosidosis. There is a vacuolation of neurones and glial cells throughout the dog brain and vacuolation is also present in epithelial cells of bronchi, bile duct tubules and lymphocytes. The disease is characterised biochemically by a deficiency of α-L-fucosidase in all cells and tissues and by the accumulation in tissues and excretion in urine of fucose-containing glycoasparagines [4]. Information concerning the mode of inheritance and molecular basis of the enzymic defect in canine fucosidosis is presented in this paper.