[Lysosomal membrane transport disorders--cystinosis and sialic acid storage disorders (Salla disease, ISSD)].

Cystinosis and sialic acid storage diseases (Salla disease, ISSD; infantile sialic acid storage disease) are lysosomal membrane disorders resulting from defective carrier-mediated transport of cystine and sialic acid across the lysosomal membrane. Both are rare autosomal recessively inherited disorders. The major clinical manifestations of cystinosis are renal failure and ocular damages. Sialic acid storage diseases are characterized by various degrees of psychomotor retardation. Salla disease patients trace a mild clinical course, and the life span is relatively long. While, in patients with ISSD follow a very severe progressive clinical course and often die in the first year of life. The genes responsible for each disease have not been isolated, the etiologies are not well known, and there is no specific treatment.