What is the gene product for Tay-Sachs disease?

• A. Beta Globin
• B. Tyrosinase
• C. HexA
• D. Cystic fibrosis transmembrane conductance regulator

Answer: (C)

Tay-Sachs disease is caused by a deficiency in a specific enzyme essential for lipid metabolism, particularly in the breakdown of gangliosides. The gene product responsible for this enzyme is known as HexA, which is short for hexosaminidase A. HexA is a lysosomal enzyme that breaks down GM2 gangliosides into GM3 gangliosides. In Tay-Sachs, mutations in the HEXA gene lead to a deficiency of HexA, resulting in the accumulation of GM2 gangliosides, which is toxic to nerve cells and leads to the symptoms associated with the disease.

The other options represent different gene products unrelated to Tay-Sachs. For example, beta globin is involved in hemoglobin formation and associated with disorders like sickle cell anemia. Tyrosinase is an enzyme critical for melanin production, linked to conditions like albinism. The cystic fibrosis transmembrane conductance regulator (CFTR) is a protein that regulates chloride channels and is associated with cystic fibrosis. Therefore, HexA is the correct answer as it directly relates to the biochemical basis of Tay-Sachs disease.