Summary
Fucosidosis is a very rare lysosomal storage disorder belonging to the group of oligosaccharidoses or glycoproteinoses. Less than 100 cases have been documented (20 of them in Southern Italy). Clinical signs include facial dysmorphism, dysostosis multiplex, moderate hepatomegaly, severe intellectual deficit , deafness, and according to age, angiokeratomas. Every intermediate form exists, ranging from severe (type 1: onset between 3 and 18 months of age) to moderate (type 2, with a slower progression). It is caused by an alpha-L-fucosidase deficiency, responsible for generalized accumulation of fucose-containing glycolipids and oligosaccharides in body tissues. Transmission is autosomal recessive. The gene has been located on 1p36-p34 (FUCA 1 locus) and cloned, together with a pseudogene on chromosome 2. More than 20 mutations have been identified. Moreover, a polymorphic locus (FUCA 2) on chromosome 6 has been associated with control of enzymatic activity levels in serum and fibroblasts. Biological diagnosis is made by finding the typical chromatographic profile of urinary oligosaccharides. Results are confirmed by measuring the alpha-L-fucosidase activity in leucocytes. Some difficulties have been encounterd when measuring enzyme activity in ammniocytes and in the trophoblast. The only specific treatment is allogenic bone marrow transplantation, but less than 10 cases have been transplanted worldwide and it is too soon to assess the results. *Authors: Dr R. Froissart, Dr I. Maire (February 2005)*.
