Histology: basement membrane collagen: practice question

A Anatomy 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

Anatomy · Histology: basement membrane collagen

Sample item

A 9-year-old boy has recurrent haematuria, high-tone sensorineural hearing loss and anterior lenticonus. His maternal uncle died of renal failure. Electron microscopy of his glomerulus shows a split and lamellated basement membrane. Which structural protein is defective?

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

The answer and the reasoning

A. Type IV collagen

This is Alport syndrome, usually X-linked, caused by mutations in the alpha-5 chain of type IV collagen. Type IV collagen forms the sheet-like network of the basement membrane of the glomerulus, cochlea and lens capsule, which explains the kidney, ear and eye findings.

Option by option

  • A. Type IV collagen (correct)

    Correct. Type IV collagen is the main collagen of basement membranes in the glomerulus, cochlea and lens.

  • B. Type III collagen

    Type III collagen forms reticular fibres and is defective in vascular Ehlers-Danlos syndrome.

  • C. Type I collagen

    Type I collagen is the main collagen of bone, tendon and skin and is defective in osteogenesis imperfecta.

  • D. Type II collagen

    Type II collagen forms hyaline cartilage and vitreous and is affected in some chondrodysplasias.

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 Anatomy questions

Questions about this Anatomy question

What is the answer to this Anatomy question?

The best answer is A, Type IV collagen. This is Alport syndrome, usually X-linked, caused by mutations in the alpha-5 chain of type IV collagen.

Why is "Type III collagen" not the answer?

Type III collagen forms reticular fibres and is defective in vascular Ehlers-Danlos syndrome.

Why is "Type I collagen" not the answer?

Type I collagen is the main collagen of bone, tendon and skin and is defective in osteogenesis imperfecta.

Why is "Type II collagen" not the answer?

Type II collagen forms hyaline cartilage and vitreous and is affected in some chondrodysplasias.

What concept does this question test?

It tests Histology: basement membrane collagen in Anatomy. Type IV collagen forms the sheet-like network of the basement membrane of the glomerulus, cochlea and lens capsule, which explains the kidney, ear and eye findings.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Histology: basement membrane collagen?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy 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.