Fucosidosis is an extremely rare lysosomal storage disorder characterized by a highly variable phenotype with common manifestations including neurologic deterioration, coarse facial features, growth retardation, and recurrent sinopulmonary infections, as well as seizures, visceromegaly, angiokeratoma and dysostosis. The disease is Monarch Disease Ontology identifier MONDO_0009254 (fucosidosis). Also known as: A-fucosidase deficiency, Alpha-L-fucosidase deficiency, alpha fucosidase deficiency.