Question

Accumulation of sphingomyelin in phagocytic cells is a feature of

• A. Gaucher's Disease
• B. Niemann-Pick Disease
• C. Tay-Sachs Disease
• D. Down's syndrome

Hint:

Sphingomyelinase deficiency causes sphingomyelin buildup, this is Niemann-Pick disease.

Answer 1

The Correct Option is B

This question is about matching a stored lipid, sphingomyelin, to the correct lysosomal storage disease.

1. Gaucher's Disease: This disease comes from low glucocerebrosidase activity, so the stored lipid is glucocerebroside, seen inside macrophages called Gaucher cells, not sphingomyelin.
2. Niemann-Pick Disease: Here the enzyme sphingomyelinase is deficient, so sphingomyelin cannot be broken down and piles up inside lysosomes of phagocytic cells, forming lipid laden foam cells. This is the exact match for the question.
3. Tay-Sachs Disease: This condition comes from a lack of hexosaminidase A, leading to build up of GM2 ganglioside mainly inside neurons, not sphingomyelin in phagocytes.
4. Down's syndrome: This is caused by an extra copy of chromosome 21, a chromosomal disorder, and has nothing to do with enzyme deficiency or lipid storage.

Since sphingomyelin accumulation specifically points to a missing sphingomyelinase enzyme, the correct disease is Niemann-Pick disease.

Let's summarize:

• Niemann-Pick disease: sphingomyelinase deficiency, sphingomyelin accumulates.
• Gaucher's disease: glucocerebrosidase deficiency, glucocerebroside accumulates.
• Tay-Sachs disease: hexosaminidase A deficiency, GM2 ganglioside accumulates.

So the correct answer is Niemann-Pick disease.