A 3-year-old boy has coarse facial features, corneal clouding, hepatosplenomegaly, developmental regression, kyphosis, and umbilical hernia. Urine shows increased dermatan and heparan sulphate. Enzyme assay shows absent α-L-iduronidase. Which disorder is this?
- A Hurler syndrome (MPS I-H) ✓
- B Hunter syndrome (MPS II)
- C Morquio syndrome (MPS IV)
- D Sanfilippo syndrome (MPS III)
Explanation
Hurler syndrome (Mucopolysaccharidosis type I-H) is caused by deficiency of α-L-iduronidase leading to accumulation of dermatan sulphate and heparan sulphate. Features include coarse facies, corneal clouding, hepatosplenomegaly, progressive intellectual deterioration, kyphosis, joint stiffness, and cardiac valve disease. Autosomal recessive inheritance. Hunter syndrome (MPS II) is X-linked, lacks corneal clouding, and has iduronate-2-sulphatase deficiency. Morquio has skeletal dysplasia with normal intellect. Sanfilippo presents with severe neurological deterioration and mild somatic features, primarily heparan sulphate accumulation.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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