Context

• A baby was born using three persons’ DNA in the UK. 
• The baby has three parents, technically, deriving the mitochondria from a donor apart from genetic material (DNA) from biological parents. 

What is mitochondria

• Mitochondria are basically the powerhouses of the cells, they generate the energy, and thus are also responsible for cell function in the human body.

Mitochondrial Diseases

• Certain defects might occur impacting on the way the mitochondria produces energy for the cells , and thereby impacting cell function.
• The diseases that arise out of such mitochondrial mutations are called mitochondrial diseases. 
• When the mitochondria are impaired and do not produce sufficient energy, that affects how the organs function, leading to a broad assortment of symptoms across the body, including brain damage, organ failure and muscle wastage.

Mitochondrial donation treatment

• Mitochondrial diseases are only passed on by the mother
• through an advanced In Vitro Fertilisation technique, the baby’s biological father’s sperm was used to fertilise the eggs from the biological mother, who has a mitochondrial disease, and a third, female donor with clear mitochondria, separately.
• Then, the nuclear genetic material from the donor’s egg is removed and replaced with the genetic material from the biological parents’. 
• The final product – the egg – which has the genetic material (DNA) from the parents, and the mitochondria from the female donor, is implanted in the uterus, and carried to full term to yield a baby who will be free from the mother’s mitochondrial disease. 
• This process is termed Mitochondrial Donation Treatment (MDT).

https://www.thehindu.com/sci-tech/health/babys-got-three-parents-explaining-mitochondrial-donation-treatment/article66841615.ece