[Mucopolysaccharidosis. Nosology--clinical aspects--therapeutic approaches]

The mucopolysaccharidoses represent a group of lysosomal storage disorders characterized by coarse facies, skeletal deformities, and often mental deterioration. Recent clinical and biochemical studies have revealed a broad genetic heterogeneity of these metabolic diseases: An identical enzyme defect may lead to a mild form with normal adult height and normal life expectancy or to a severe hydrops fetalis that does not survive the first days of life. Conversely, Sanfilippo disease is an example that identical phenotypes may result from mutations of different genes. From clinical observations it became clear, that not only the skin, brain and skeletal system are involved in the storage process, but also the lungs and the cardiovascular system. Until recently, no more than palliative treatment could be offered. This consists of corneal transplantation, cervical fusion to prevent atlantoaxial subluxation, especially in Morquio's disease, and shunt operation to relieve hydrocephalus. In the last decade bone marrow transplantation became available; this may have beneficial effects in selected cases, especially in mucopolysaccharidosis I. Since the genes of several lysosomal enzymes have been identified, many efforts to introduce the normal gene into the affected cells were done. This method was successfully applied in an animal model. But many efforts in several laboratories are still necessary until this therapeutic regimen will become available for patients with mucopolysaccharidosis.