Lysosomal accumulation of sphingomyeline is seen in
**Core Concept**
Lysosomal storage diseases occur due to the deficiency of enzymes responsible for the breakdown of various substrates within lysosomes. Sphingomyelin is a type of sphingolipid, and its accumulation in lysosomes is characteristic of a specific disease.
**Why the Correct Answer is Right**
The correct answer is related to Niemann-Pick disease, a group of lysosomal storage disorders caused by the deficiency of acid sphingomyelinase (ASM). This enzyme catalyzes the breakdown of sphingomyelin into ceramide and phosphocholine. In the absence of ASM, sphingomyelin accumulates in lysosomes, leading to cellular dysfunction and disease. This accumulation is a hallmark of Niemann-Pick disease type A and B.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not relate to the lysosomal accumulation of sphingomyelin. The correct association is with Niemann-Pick disease.
* **Option B:** This option is incorrect because it refers to a different type of lysosomal storage disease, Gaucher's disease, which is associated with the accumulation of glucocerebroside.
* **Option C:** This option is incorrect because it is not a recognized lysosomal storage disease. The correct association is with Niemann-Pick disease.
* **Option D:** This option is incorrect because it is not directly related to the lysosomal accumulation of sphingomyelin. The correct association is with Niemann-Pick disease.
**Clinical Pearl / High-Yield Fact**
Niemann-Pick disease is characterized by the accumulation of sphingomyelin in lysosomes, leading to cellular dysfunction and disease. This accumulation is a result of the deficiency of acid sphingomyelinase (ASM), an enzyme responsible for the breakdown of sphingomyelin.
**Correct Answer:** D. Niemann-Pick disease.