Heritable disorders of mucopolysaccharide metabolism.

The heritable diseases of mucopolysaccharide metabolism have undergone reclassification during the past several years as a result of advances in knowledge. Recognition of clinical, genetic and biochemical differences has made it possible to delineate six types of mucopolysaccharidosis. All types are characterized by excessive excretion of one or more acid mucopolysaccharides in the urine. The underlying defect is not known at present, but recent investigations have suggested possible defects in protein binding and increased biosynthesis and storage of the various mucopolysaccharides. Treatment of these disorders has been unrewarding, although administration of corticosteroids may be of some benefit.Several diagnostic tests are now available for the determination of excessive urinary acid mucopolysaccharide excretion.