Question

A child with coarse facial features and developmental delay is found to have a deficiency of $\alpha$-L-iduronidase on enzyme testing. Which substances are expected to accumulate in this disorder?

• A. Dermatan sulfate + Chondroitin sulfate
• B. Only Dermatan sulfate
• C. Dermatan sulfate + Heparan sulfate
• D. Heparan sulfate + Chondroitin sulfate

Hint:

Hurler syndrome = $\alpha$-L-iduronidase deficiency = accumulation of dermatan sulfate and heparan sulfate.

Answer 1

The Correct Option is C

Concept: Deficiency of $\alpha$-L-iduronidase causes Hurler syndrome, a mucopolysaccharidosis. In this condition, dermatan sulfate and heparan sulfate accumulate.

Step 1: Identify the enzyme deficiency.
The enzyme deficient is: \[ \alpha\text{-L-iduronidase} \] This is seen in Hurler syndrome.

Step 2: Identify the disease group.
Hurler syndrome belongs to mucopolysaccharidoses, where glycosaminoglycans accumulate.

Step 3: Recall the accumulated substances.
The substances accumulated are: \[ \text{Dermatan sulfate + Heparan sulfate} \] Therefore, the correct answer is Dermatan sulfate + Heparan sulfate.