Tissue alpha-L-fucosidase (FUCA1) is a lysosomal enzyme that removes terminal L-fucose residues from the oligosaccharide chains of N-glycoproteins (NGPs). In humans, FUCA1 encodes the tissue enzyme, whilst FUCA2 encodes plasma alpha-L-fucosidase (Intra et al. 2007). Defects in FUCA1 can cause fucosidosis (FUCA1D; MIM:230000), a rare lysosomal storage disorder characterised by progressive psychomotor deterioration, angiokeratoma and growth retardation (Willems et al. 1999).