Which of the following occurs in the lipidosis known as Tay-Sachs disease?
**Core Concept**
Tay-Sachs disease is a genetic disorder caused by a deficiency of the enzyme hexosaminidase A (Hex-A), leading to the accumulation of ganglioside GM2 within neurons. This accumulation is due to the inability to break down GM2, resulting in neuronal damage and death.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of Tay-Sachs disease. Hexosaminidase A is a crucial enzyme responsible for the breakdown of GM2 gangliosides into their constituent sugars. In Tay-Sachs disease, the deficiency of Hex-A leads to the accumulation of GM2 within neurons, causing cell death and progressive neurological deterioration. The inability to break down GM2 is due to the absence of the alpha-subunit of Hex-A, which is encoded by the HEXA gene.
**Why Each Wrong Option is Incorrect**
* **Option A:** This is not accurate, as Tay-Sachs disease is not caused by a deficiency of alpha-galactosidase.
* **Option B:** This is incorrect, as Fabry disease is a separate genetic disorder caused by a deficiency of alpha-galactosidase.
* **Option C:** This is not related to Tay-Sachs disease, as Niemann-Pick disease type A is caused by a deficiency of acid sphingomyelinase.
**Clinical Pearl / High-Yield Fact**
Tay-Sachs disease is an autosomal recessive disorder, meaning that individuals must inherit two copies of the mutated gene (one from each parent) to develop the disease. This knowledge is essential for genetic counseling and diagnosis.
**Correct Answer:** C.