Mitochondrial Replacement Therapy (MRT)

Syllabus: GS3/Science and Technology

Context

• Eight healthy babies were born in Britain with the help of an experimental technique called Mitochondrial Replacement Therapy (MRT).

About

• The mothers were all at high risk for passing on life-threatening diseases to their babies due to mutations in their mitochondria.
• The four boys and four girls were born to seven women and have no signs of the mitochondrial diseases they were at risk of inheriting.
• The UK became the first country to approve the use of mitochondrial donation in 2015.
• The procedure is not yet permitted in India.

Mitochondrial Genes

• Mitochondria: The human genes are curled up in the nucleus of nearly every cell in the body.
  • The fluid surrounding the nucleus contains hundreds to thousands of mitochondria that carry their own set of 37 genes. 
  • The mitochondria are membrane-bound organelles often referred to as the “powerhouses of the cell” because they play a crucial role in producing energy.

• People inherit all their mitochondria from their biological mother, mutations can affect all the children a woman has.
• Mutations in these genes can impair or completely disable mitochondria with catastrophic effects.
  • The first symptoms of mitochondrial disease tend to appear in early childhood as energy-hungry organs such as the brain, heart and muscles start to fail. 
  • Many affected children have developmental delays, require wheelchairs and die young. About one in 5,000 newborns are affected.

Mitochondrial Donation Treatment (MDT)

• A three-parent baby is produced from the genetic material of one man and two women through mitochondrial replacement therapy (MRT) and three-person in vitro fertilization (IVF).
• Aim: To prevent children from inheriting mutated mitochondria. 
• Procedure: It involves fertilising the mother’s egg with the father’s sperm and then transferring the genetic material from the nucleus into a fertilised healthy donor egg that has had its own nucleus removed.
  • This creates a fertilised egg with a full set of chromosomes from the parents, but healthy mitochondria from the donor. 
  • The egg is then implanted into the womb to establish a pregnancy.

• These babies carry nuclear DNA from their biological mother and father, and a small portion of mitochondrial DNA from a female donor.

Conclusion

• Scientists around the world are closely watching the UK’s results. 
• Many believe that with careful regulation, MDT could become a routine option for families at risk, helping to stop certain genetic diseases before they begin.

Source: LM