Gangliosides deficiency disease

Farber s disease is a rare disorder caused by deficiency of acid ceramidase and is associated with the accumulation of ceramide in subcutaneous tissues, joints, kidney, lung and neurons. Gangliosides also accumulate. 

The biochemical defect In Tay-Sachs disease is an inherited deficiency of -hexosaminidase, a lysosomal enzyme responsible for hydrolysis ofGM2 ganglioside, which accumulates abnormally in the lyso-somes. 

Hexoseamidase A is the enzyme which is deficient in Tay-Sachs disease. This inherited condition results in an accumulation of GM2 gangliosides (sphingolipids) in the brain. The consequences are mental retardation, paralysis, blindness and death by the age of 3-4 years. 

Tay-Sachs disease. A member of a family of disorders identified as the Gm2 gangliosidoses. As neural cell membranes are enriched in Gm2 gangliosides, the inability to degrade this class of sphingolipid resnlts in neural cell death. In addition to Tay-Sachs disease the family includes the Sandhoff diseases and the Gm2 activator deficiencies. Tay-Sachs disease resnlts from defects in the HEXA gene encoding the a-subunit of /3-hexosaminidase. 

E. Because a hexosaminidase is deficient in Tay-Sachs disease, partially degraded sphin-golipids (gangliosides) accumulate in lysosomes. 

Tay-Sachs disease is a lipid storage disease caused by an absence of the enzyme hexosaminidase, which functions in gan-glioside metabolism. As a result of the enzyme deficiency, the ganglioside, shown in Section 18.4, accumulates in the cells of the brain causing neurological deterioration, like Niemann-Pick disease, it is an autosomal recessive genetic trait that... 

GM2 gangliosidosis is a family of autosomal recessive disorders characterized by accumulation of GM2 ganglioside and its related glycolipids in the neuronal lysosome. It comprises GM2 activator protein deficiency, Tay-Sachs and Sandhoff disease, the latter of which are caused by a deficiency in the a-subunit or B-subunit of B-hexosaminidase, respectively (Gravel et ah, 1995). 

Tay Sachs disease P-hexosamlnIdase A deficiency causes gangliosides to accumulate... 

In addition to an enzyme, the presence of the GM2-activator protein in vivo or of a detergent in vitro is required for the digestion of ganglioside GM2. Mutations in the gene of the P-hexosaminidase a-chain in human patients leads to Tay-Sachs disease, and mutations in the P-chain lead to Sandhoff disease. Together with GM2-activator protein deficiency, these diseases belong to the GM2-gangUosidoses. 

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