MDT

Q. With reference to the mitochondrial donation technique (MDT) recently used in the UK, consider the following statements:

1. The technique involves replacing faulty mitochondrial DNA in a woman’s egg with healthy mitochondrial DNA from a donor to prevent transmission of mitochondrial diseases.
2. The resulting child inherits genetic material from three individuals, with the donor’s contribution forming a significant portion of the baby’s total DNA.
3. Mitochondrial defects can lead to severe health problems affecting critical organs like the brain, heart, and muscles, which MDT aims to prevent.

Which of the above statements is/are correct?

A. 1 and 3 only
B. 1 and 2 only
C. 2 and 3 only
D. 1, 2 and 3

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Correct Answer: A. 1 and 3 only

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Explanation:

• Statement 1 is correct: MDT works by replacing faulty mitochondrial DNA with healthy mitochondria from a donor egg to prevent transmission of mitochondrial diseases.
• Statement 2 is incorrect: Although the child inherits DNA from three people (mother, father, and donor), the donor’s contribution is less than 1% of total DNA — it is not significant in the genetic sense.
• Statement 3 is correct: Mitochondrial disorders can indeed affect vital organs like the brain, heart, and muscles, and are often fatal or severely debilitating — MDT is intended to prevent these outcomes.