Fucosidosis

Fucosidosis is a rare inherited lysosomal storage disorder in which mutations in the FUCA1 gene severely reduce or stop the activity of the enzyme alpha-L-fucosidase. Without the enzyme, fucose-containing glycolipids and glycoproteins are not fully broken down and build up in cells, and brain cells are especially sensitive to the buildup. The result is progressive neurological decline, intellectual disability, seizures, coarse facial features, skeletal disease, growth retardation, skin abnormalities and an enlarged liver and spleen. It is inherited in an autosomal recessive pattern, so both parents must carry the variant, and each child of two carriers has a 25 percent chance of being affected. Fucosidosis was first described in 1962 in two Italian siblings. It was once split into a severe type 1 and a milder type 2 but is now regarded as one disease spectrum. Fewer than 200 cases have been reported, mostly from Italy, Cuba and the southwestern United States. Diagnosis rests on a urine test for partly broken-down sugars and a blood or skin test for low alpha-fucosidase. Treatment is aimed at symptoms such as seizures, and research on bone marrow transplant continues. Canine fucosidosis occurs in the English Springer Spaniel. This entry records what is known and is not medical advice.