In Maroteaux- Lamy syndrome, the enzyme deficient is?
**Core Concept**
Maroteaux-Lamy syndrome, also known as Mucopolysaccharidosis VI (MPS VI), is a rare genetic disorder caused by the deficiency of a specific enzyme involved in the breakdown and recycling of glycosaminoglycans (GAGs). This enzyme is crucial for the degradation of dermatan sulfate, a type of GAG found in connective tissue.
**Why the Correct Answer is Right**
The correct answer, Arylsulfatase B, is a lysosomal enzyme responsible for the hydrolysis of N-acetylgalactosamine-4-sulfate from dermatan sulfate. In Maroteaux-Lamy syndrome, the deficiency of Arylsulfatase B leads to the accumulation of dermatan sulfate in various tissues, causing a range of clinical manifestations, including short stature, coarse facial features, and joint stiffness. This enzyme deficiency results in the inability to break down and recycle dermatan sulfate, leading to its accumulation and subsequent tissue damage.
**Why Each Wrong Option is Incorrect**
**Option A:** Arylsulfatase B is the correct enzyme deficient in Maroteaux-Lamy syndrome, making this option incorrect.
**Option B:** Glucosidase is an enzyme involved in the breakdown of glycogen and is deficient in Pompe disease, not Maroteaux-Lamy syndrome.
**Option C:** Hydroxylase is a class of enzymes involved in various biochemical reactions, but it is not the enzyme deficient in Maroteaux-Lamy syndrome.
**Option D:** β-glucuronidase is an enzyme involved in the breakdown of glucuronic acid-containing GAGs, but it is deficient in Sly syndrome (MPS VII), not Maroteaux-Lamy syndrome.
**Clinical Pearl / High-Yield Fact**
To differentiate Maroteaux-Lamy syndrome from other mucopolysaccharidoses, it's essential to note that the clinical presentation and biochemical findings are unique to each disorder. A thorough understanding of the specific enzyme deficiencies and their corresponding clinical manifestations is crucial for accurate diagnosis and management.
**✓ Correct Answer: A. Arylsulfatase B**