Fucosidosis is an autosomal recessive disorder caused by a deficiency of alpha-L-fucosidase. Up to now 79 cases have been described and several others identified but not yet published. The higher incidence of the disease is in Italy, where nearly 20 patients have been identified. Fourteen disease-causing mutations have been detected and four of them, Q422X, G60D, E375X, P141fs are present in more than 70% of the forty patients studied. In Italian patients, only seven mutations have been described and P141fs and G60D mutations are present in more than 50% of the cases. The P141fs mutation is absent in other ethnic groups. It has been impossible to establish genotype-phenotype correlation so far and the clinical variability of the disease cannot be explained only by genetic heterogeneity.
