Inborn Errors of Complex Carbohydrate Catabolism

摘要: Complex carbohydrates of the nervous system are degraded in lysosomes by sequential action a group exoglycosidases known collectively as lysosomal hydrolases. Inherited defects synthesis, assembly, or turnover these hydrolases lead to storage diseases humans (Spranger, 1987) and variety domestic animals. Those involving result spectacular neuropathology provide best evidence for types glycoconjugates synthesized tissue, well their rate turnover. For example, Tay—Sachs disease, material (GM2 ganglioside) predominates especially motor neurons, is virtually absent from visceral tissue. The variable level accumulation GM2 different brain regions (identified morphologically multilamellar cytosomes) can be related levels synthesis degradation. This clearly manifests itself patients with partial hexosaminidase (HexA) deficiencies, who exhibit symptoms neuron spinocerebellar degeneration other neuronal function (such vision intelligence) relatively intact. absence outside CNS reflects lack nonneural However, since constitutively all tissues, fed fibroblasts HexA-deficient patients, its steady observed. Thus, patterns inherited enzyme used give an accurate reflection glycoconjugate content versus tissue this will emphasized on enzyme/disease, case-by-case basis.