Mitochondrial donation treatment

Context: A baby was born in the U.K. using three persons’ DNA through a process called Mitochondrial donation treatment.

The baby, technically, has three parents– genetic material (DNA) from two biological parents and mitochondria from one donor parent (female donor). The technology was used to prevent the child from inheriting the mother’s mitochondrial disease.

What is Mitochondria?

• Mitochondria are tiny organelles inside cells that are often referred to as the powerhouses of the cell. 
  • Mitochondria occur in large numbers in most of our cells, except for red blood cells.
• It converts the energy molecules which we get from food to usable energy molecules called ATP (Adenosine triphosphate) through a process known as cellular respiration. 

Mitochondrial disease: 

• Mitochondria generate energy and thus are responsible for cell function in the human body. However, when the mitochondria are impaired they do not produce sufficient energy which affects how organs function. 
• Faulty mitochondria can cause inherited conditions such as fatal heart problems, liver failure, brain disorders, blindness and muscular dystrophy. The diseases that arise out of such mitochondrial mutations are called mitochondrial diseases.
  • Mitochondrial diseases are only passed on by the mother. 
• The symptoms get more pronounced as a child grows, and there is no cure for mitochondrial DNA disease at present.
  • Some estimates put the incidence of mitochondrial diseases as one in 5,000 people. 

Mitochondrial Donation Treatment: 

• Mitochondrial donation involves replacing unhealthy mitochondria in the mother with healthy mitochondria from a donor during the in vitro fertilisation (IVF) process.
  • Mitochondria have their own DNA, distinct from that in a cell’s nucleus. It does not influence appearance, personality or other human characteristics.

The process:

• Through the IVF technique, the baby’s biological father’s sperm was used to fertilise the eggs from the biological mother, who has mitochondrial disease, and a third, female donor with clear mitochondria, separately.
• Then, the nuclear genetic material from the donor’s egg was 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).
• With this process, the final cytoplasm (which holds the genetic material and mitochondria) has healthy mitochondria while the genetic material belongs to the biological parents.
• Side effects: While largely helpful, the procedure has some minimal risks that sometimes a small amount of the maternal mitochondria with errors may get passed on during the procedure.