Retinoblastoma: genetics: practice question

A Ophthalmology 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

Ophthalmology · Retinoblastoma: genetics

Sample item

Which statement regarding the retinoblastoma gene is correct?

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

The answer and the reasoning

D. It is a tumour suppressor gene at 13q14 and two hits are needed

RB1 is a tumour suppressor gene, with Knudson's two-hit hypothesis. In the hereditary form one hit is germline and a second somatic hit leads to bilateral multifocal tumours and risk of secondary tumours such as osteosarcoma.

Option by option

  • A. It needs only one somatic hit in the hereditary form

    A second somatic hit is still required in hereditary disease.

  • B. It is an oncogene at 11p13

    11p13 is the Wilms tumour and aniridia locus.

  • C. It is located on chromosome 17

    Chromosome 17 carries TP53 and NF1.

  • D. It is a tumour suppressor gene at 13q14 and two hits are needed (correct)

    Correct. RB1 lies at 13q14.

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 Ophthalmology questions

Questions about this Ophthalmology question

What is the answer to this Ophthalmology question?

The best answer is D, It is a tumour suppressor gene at 13q14 and two hits are needed. RB1 is a tumour suppressor gene, with Knudson's two-hit hypothesis.

Why is "It needs only one somatic hit in the hereditary form" not the answer?

A second somatic hit is still required in hereditary disease.

Why is "It is an oncogene at 11p13" not the answer?

11p13 is the Wilms tumour and aniridia locus.

Why is "It is located on chromosome 17" not the answer?

Chromosome 17 carries TP53 and NF1.

What concept does this question test?

It tests Retinoblastoma: genetics in Ophthalmology. In the hereditary form one hit is germline and a second somatic hit leads to bilateral multifocal tumours and risk of secondary tumours such as osteosarcoma.

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 Retinoblastoma: genetics?

Group the red eye by what to examine and what the pupil does. Then use the flashcards and the other Ophthalmology 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.