Tay-Sachs disease is primarily caused by a defect in which enzyme?

• A. Hexosaminidase B
• B. Hexosaminidase A
• C. Beta-glucosidase
• D. Acetylcholinesterase

Answer: (B)

Tay-Sachs disease is primarily caused by a deficiency in the enzyme Hexosaminidase A. This enzyme is crucial for the metabolism of certain lipids, particularly GM2 gangliosides, which are fatty substances that accumulate in nerve cells. When Hexosaminidase A is not functioning properly due to a genetic mutation, the body cannot break down GM2 gangliosides effectively, leading to their accumulation. This buildup disrupts normal cellular function and ultimately leads to the neurodegenerative symptoms characteristic of Tay-Sachs disease.

Understanding this mechanism highlights the importance of specific enzymes in metabolic pathways, especially in the context of genetic disorders. The other options involve enzymes that are not implicated in Tay-Sachs disease, making them unrelated to the condition.