Answer Writing Practice for UPSC IAS Mains Exam: Paper - IV (General Studies – III) - 26 September 2018

Answer Writing Practice for UPSC IAS Mains Exam

UPSC Syllabus:

  • Paper-IV: General Studies -III (Technology, Economic Development, Bio-diversity, Environment, Security and Disaster Management)

Q. Discuss how the Mitochondrial Gene Therapy is helpful in the process of three parent embryo development. (250 words)

Model Answer:


  • Why in news
  • Introduction
  • Mitochondrial Gene Therapy
  • Three-Parent Embryo Developments
  • Challenges and Issues
  • Conclusion

Why in news

UK has become the only country so far to have officially approved the use of a mitochondrial replacement therapy (MRT) technique, and only to prevent children from inheriting severe mitochondrial disorders. Three-parent babies could be born in the UK this year. Two cases have been approved by the UK’s Human Fertilization and Embryology Authority (HFEA) to take place at Newcastle’s Fertility Centre at Life.


Mitochondria, the powerhouse of the cell, have its own set of generic material called mitochondrial DNA or mtDNA. It is inherited maternally. Various mitochondrial disorders exist due to mutations in these DNA and result in visual losses, diabetes, hearing impairment, stunted growth, etc. and finally pre-mature death.

Mitochondrial replacement technique is used to avoid defective mtDNA from passing down to the next generation. Here the nuclear DNA of patient mother isused to replace that in the donor mother's eggs and the latter already had healthy mitochondria. Then In Vitro Fertilization is done with partner's sperm. Thus, the baby is effectively 3-parent and has healthy mitochondria.

Mitochondrial Gene Therapy

Mitochondria are peanut-shaped cytoplasmic organelles inside cells that generate energy: Specifically, they convert the calories contained in foods into a molecule [adenosine triphosphate (ATP)] that cells can use for energy. The proteins for most organelles are encoded entirely in the cell's nuclear genome, but mitochondria carry a small amount of mitochondrial DNA (mtDNA) for unique proteins essential to them. One further distinguishing feature of the mtDNA is that it is inherited only from the mother because no mitochondria are passed along by a fertilizing sperm.

But to prevent some defects in maternal mtDNA from being passed down between generations, researchers have developed a new genetic technique called mitochondrial replacement therapy (MRT).

Mitochondrial Gene therapy is a groundbreaking technique that uses genetic material from three different people to prevent certain inherited –genetic disorders from passing from mother to her offspring’s.

Three Parent Embryo Developments

  • The healthy nuclear DNA is removed by patient’s egg cell leaving behind faulty mitochondrial DNA.
  • Patient’s nuclear DNA will be transplanted to donor’s egg with healthy mitochondrial DNA.
  • Therefore by replacing the dysfunctional mitochondria carried by woman who wishes to conceive a child with the healthy mitochondria of a donor.
  • Egg is then fertilized with partner’s sperm through In Vitro Fertilization.
  • The embryo thus created is one technically cleansed of the mutated mitochondrial DNA that the mother originally carried.
  • The reconstructed egg cell fertilized with sperm in the lab and implanted into mother and thus resulted embryo will have three genetic parents.


Challenges and Issues

  • Church has opposed this move saying it would lead to Frankenstein babies who will not recognize their parents and alter human race. This may be the first step towards a market of designer babies.
  • Opponents believe this method would cause a loss of sense of identity and cause emotional and psychological suffering to the child.
  • Opponents say that this technique to tantamount to playing with God and will alter the human germ line. These modifications will be passed to subsequent generations.
  • Opponents also argue that a child has right to fully inherit all genetic material from parents with all its deficiencies as well.
  • The efficacy and safety of this technique is yet to be demonstrated.  Some argue that it is better to have pre-natal diagnosis and if fetus is found defective, terminate pregnancy.


The mitochondrial gene therapy is a miracle in the life science as it can deal with the issues pertaining to inherited genetic diseases and may become a panacea to all the problems caused due to faulty genetic structures. The various ethical issues related to this technology can be sorted out through consensus building exercises but overall this technology is a boon to the entire society.

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