Context

In Britain, eight healthy babies were recently born using an innovative technique called Mitochondrial Replacement Therapy (MRT), which is still considered experimental.

Background

The mothers involved carried mutations in their mitochondria that put their children at high risk of inheriting severe, life-threatening mitochondrial diseases. The group of babies—four boys and four girls—were born to seven different women and show no signs of the mitochondrial disorders they might have inherited.

Regulatory Status

The UK became the pioneer by approving mitochondrial donation in 2015, becoming the first country to legalize this therapy. However, this technique is not yet approved for use in India.

Understanding Mitochondrial Genes

• Mitochondria are tiny structures within cells, found in the fluid outside the nucleus. While human DNA is mainly stored in the cell’s nucleus, mitochondria contain their own distinct DNA comprising 37 genes.
• Known as the “powerhouses of the cell,” mitochondria generate energy essential for cell function.
• Importantly, mitochondria—and their DNA—are inherited exclusively from the mother. If a mother’s mitochondria have genetic mutations, all her children are at risk of inheriting these defects.
• Such mutations can severely impair mitochondria, leading to catastrophic effects, especially in organs that need lots of energy such as the brain, heart, and muscles.
• Symptoms usually manifest early in life and can include developmental delays, physical disabilities, and premature death. Mitochondrial diseases affect roughly 1 in every 5,000 newborns.

What is Mitochondrial Donation Therapy (MDT)?

Also known as the creation of a "three-parent baby," this therapy involves genetic material from one father and two mothers (one being the mitochondrial donor). The goal is to prevent the transmission of faulty mitochondria.

Procedure:

1. The mother’s egg is fertilized with the father’s sperm.
2. The nucleus, containing most of the genetic material, is removed from this fertilized egg.
3. This nucleus is then transferred into a donor egg, which has had its own nucleus removed but contains healthy mitochondria.
4. The reconstructed egg now contains chromosomes from the biological parents but healthy mitochondria from the donor.
5. This egg is implanted into the mother’s womb to develop into a healthy baby.

The resulting child carries nuclear DNA from both biological parents and mitochondrial DNA from the donor.

Conclusion

Scientists worldwide are closely monitoring the UK’s experience with MRT. With appropriate regulation and oversight, mitochondrial donation therapy holds promise as a preventive measure against inherited mitochondrial diseases, potentially becoming a standard option for at-risk families.

Source: LM