Skeletal dysplasias: Morquio syndrome: practice question

A Orthopaedics question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

Try it

Orthopaedics · Skeletal dysplasias: Morquio syndrome

Sample item

A 6-year-old with normal intelligence has short trunk dwarfism, platyspondyly, corneal clouding and a hypoplastic odontoid process. Which accumulation is responsible, and which complication is feared?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Keratan sulphate; atlantoaxial instability with cord compression

Morquio syndrome (mucopolysaccharidosis IV) results from keratan sulphate accumulation. Odontoid hypoplasia causes atlantoaxial instability that may lead to cervical myelopathy, so surveillance and posterior fusion are used. Intelligence is typically normal.

Option by option

  • A. Keratan sulphate; atlantoaxial instability with cord compression (correct)

    Correct. Keratan sulphate accumulation and odontoid hypoplasia define Morquio syndrome.

  • B. Heparan sulphate alone; hydrocephalus

    Heparan sulphate accumulation is a feature of Sanfilippo syndrome with severe intellectual disability.

  • C. Homogentisic acid; ochronotic arthropathy

    Homogentisic acid accumulation causes alkaptonuria.

  • D. Glucocerebroside; Erlenmeyer flask deformity

    Glucocerebroside accumulation causes Gaucher disease.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Orthopaedics questions

Questions about this Orthopaedics question

What is the answer to this Orthopaedics question?

The best answer is A, Keratan sulphate; atlantoaxial instability with cord compression. Morquio syndrome (mucopolysaccharidosis IV) results from keratan sulphate accumulation.

Why is "Heparan sulphate alone; hydrocephalus" not the answer?

Heparan sulphate accumulation is a feature of Sanfilippo syndrome with severe intellectual disability.

Why is "Homogentisic acid; ochronotic arthropathy" not the answer?

Homogentisic acid accumulation causes alkaptonuria.

Why is "Glucocerebroside; Erlenmeyer flask deformity" not the answer?

Glucocerebroside accumulation causes Gaucher disease.

What concept does this question test?

It tests Skeletal dysplasias: Morquio syndrome in Orthopaedics. Odontoid hypoplasia causes atlantoaxial instability that may lead to cervical myelopathy, so surveillance and posterior fusion are used. Intelligence is typically normal.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Skeletal dysplasias: Morquio syndrome?

Pair each fracture with its classic complication and nerve injured. Then use the flashcards and the other Orthopaedics questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.