Mitochondrial inheritance · USMLE Step 1

If a woman carries a homoplasmic harmful mtDNA mutation, what is the risk that her child (regardless of sex) will inherit the mutation?

  1. 0%
  2. 25%
  3. 50%
  4. 100%
Show answer and explanation

Correct answer: 100%

If the mother’s mtDNA is homoplasmic (all mitochondria carry the mutation), then all her children inherit her mitochondria — so there is a 100% chance the mutation is passed to each child.

Difficulty: Medium Question 9 of 19

Practice all 19 Mitochondrial inheritance questions

Keep practicing

More Mitochondrial inheritance questions