e chromosome are needed for the catabolism of GM2 gangliosides. When these genes are mutated, the result is a buildup of the glycosphingolipid GM2 gangliosides. Over 50 mutations have been identified. Tay-Sachs disease is the most common form of gangliosidosis and results from a mutation of the alpha-subunit location on chromosome 15. This causes a severe dysfunction in the enzyme hexosaminidase A. Glycosphingolipids, otherwise known as GSLs, are components of the plasma membrane of eukaryotic cells. They interact at the cell surface with toxins, viruses, bacteria, membrane-bound receptors, and enzymes. They participate in cell-type-specific adhesion processes. The products of GSL metabolism are ceramide and sphingosine. The second step of the GSL GM1 metabolism is where the buildup of GM2 gangliosides occurs.Several alleles have been pinpointed at the alpha-subunit location. Each of these causes a variable degree of enzyme dysfunction in hexosaminidase A. These varying degrees cause varying symptoms. With the most severe allele, the infant would appear normal at birth but would begin to exhibit motor incoordination, increased startle reaction, and the cherry red spot. This would cause death by age 4. The cherry red spot is a characteristic of infantile-onset Tay-Sachs and is often used along with other characteristics for diagnosis. The juvenile-onset form is associated with ataxia and dementia. This would cause death by age 10 to 15. The adult-onset form is associated with clumsiness in childhood and motor weakness in adolescence; some patients are psychotic.The catabolism of the glycosphingolipid GM2 gangliosides requires the enzyme hexosaminidase A. In Tay-Sachs disease, an inherited disorder, a mutation on the alpha-subunit location of chromosome 15 results in a dysfunction of hexosaminidase A. This causes an accumulation of GM2 gangliosides which results in the inability of the cell to function normally. This d...
