Question

• In children who have Tay-Sachs disease, lysosomes lack a specific enzyme that breaks down certain molecules in the normal recycling of worn-out cellular membranes. Discuss this enzyme and describe the chemical manifestation of this uniformly fatal disease.

Answer 1

Tay-Sachs disease is an inherited disorder (Autosomal recessive) characterized by the destruction of nerve cells in the spinal cord and brain. The onset of disease symptoms is 3 to 6 months. Disease symptoms include inability to move, seizures, and hearing loss.

It is a caused by mutations in the HEXA gene which codes for a subunit of Hexosaminidase A. It is a lysosomal hydrolase that mediates the breakdown of sphingolipids (Hydrolysis of terminal N-acetyl-D-hexosamine residues in N-acetyl-β-D-hexosaminides). The absence of Hexosaminidase A leads to the accumulation of GM2 ganglioside in the cell leading to toxicity.