NEUROCHEMISTRY OF THE MUCOPOLYSACCHARIDOSES: BRAIN GLYCOSAMINOGLYCANS, LIPIDS AND LYSOSOMAL ENZYMES IN MUCOPOLYSACCHARIDOSIS TYPE III B (α‐N‐ACETYLGLUCOSAMINIDASE DEFICIENCY)

Glycosaminoglycans, lipids and lysosomal enzymes were measured in brain, liver and spleen of a patient with mucopolysaccharidosis Type III B (α‐N‐Acetylglucosaminidase deficiency). The glycosaminoglycan content of the brain gray and white matter, leptomeninges, spleen and liver of the patient was 4, 3, 10, and 100 times greater than that of the respective tissues of normal controls. Partially degraded heparan sulfate, the concentration of which increased 17 times in the brain, accounted for the increased glycosaminoglycan content of all tissues. The concentration of the gangliosides GM2, GM3 and GD3 was markedly increased in the gray matter, and to a smaller degree in the white matter. Ceramide dihexoside was also increased in the gray matter of the patient with MPS III B. The activity of α‐N‐Acetylglucosaminidase was absent from the brain and the liver and greatly diminished in the spleen. β‐Glucuronidase. β‐glucosaminidase and α‐l‐iduronidase were more active than normally and the activity of α‐galactosidase and β‐galactosidase was markedly reduced.