Advanced Dental Admission Test (ADAT)

What deficiency is associated with Niemann-Pick disease?

1. HMG-CoA reductase deficiency

2. Thromboxane deficiency

3. Sphingomyelinase deficiency

4. Prostaglandin deficiency

The correct answer is: Sphingomyelinase deficiency

Niemann-Pick disease is specifically linked to a deficiency in sphingomyelinase, an enzyme essential for the breakdown of sphingomyelin, a type of sphingolipid. When sphingomyelinase is deficient, sphingomyelin accumulates in various tissues, particularly in the liver, spleen, bone marrow, and brain. This accumulation leads to a range of symptoms, including hepatosplenomegaly (enlarged liver and spleen), neurological decline, and other systemic complications. Understanding the role of sphingomyelinase helps to clarify the mechanisms behind the disease, as this deficiency directly disrupts lipid metabolism, particularly affecting the nervous and hematopoietic systems. In contrast, the other options—such as HMG-CoA reductase, thromboxane, and prostaglandin deficiencies—are not related to Niemann-Pick disease and pertain to different metabolic pathways or bodily functions that do not involve sphingomyelin degradation.