The recent birth of a child in the UK with DNA from three different individuals has brought about heightened interest and discussion on the progressive science behind this groundbreaking accomplishment. This innovative method known as Mitochondrial Replacement Therapy (MRT) or three-parent IVF, intends to avoid the transmission of mitochondrial diseases.
About Mitochondria
Mitochondria are enclosed organelles discovered within the cells of the majority of eukaryotic organisms. They are frequently coined as the ‘powerhouses’ of cells since they create the bulk of the cell’s energy via adenosine triphosphate (ATP).
Functions of Mitochondria
Mitochondria execute cellular respiration, a process that transforms nutrients into ATP. These organelles convert energy from carbohydrates, fats, and proteins into a form that can be utilized by the cell. They metabolize glucose to produce ATP, which fuels various cellular processes. Furthermore, mitochondria are involved in cell signaling pathways, impacting activities like cell growth, differentiation, and apoptosis.
Inheritance of Mitochondrial DNA
Mitochondria possess their unique DNA, referred to as mitochondrial DNA (mtDNA), which encodes a limited number of vital proteins. In most animals, mtDNA is solely inherited from the mother. Any mutation within the mtDNA can result in mitochondrial disorders and various health conditions.
Mitochondrial Diseases
Specific mutations in mitochondria can result in mitochondrial diseases, affecting energy production and impacting various organs, including the brain, nerves, muscles, kidneys, heart, and liver. These diseases can cause severe symptoms such as organ failure, muscle wastage, and even brain damage. Common examples include Leigh Syndrome, Kearns-Sayre syndrome (KSS), Mitochondrial Myopathy, and Mitochondrial DNA Depletion Syndrome.
Mitochondrial Donation Treatment (MDT)/MRT
To address the problems posed by mitochondrial diseases, scientists and researchers developed an advanced In Vitro Fertilization (IVF) technique termed Mitochondrial Donation Treatment (MDT) or three-parent IVF. This technique involves a complex process that ensures the baby inherits healthy mitochondria while holding genetic materials from both biological parents.
The Scientific Process of MRT
The procedure is specifically designed for couples wanting to have their genetic child without using a donor egg. The selection of the donor and biological parents is crucial. The biological mother, diagnosed with a mitochondrial disease, provides her eggs, which are then fertilized by the biological father’s sperm. Simultaneously, another female donor with healthy mitochondria is involved. The genetic material (DNA) from the donor’s egg is extracted and replaced with the genetic material from the biological parents, which creates an embryo with the parents’ DNA and the donor’s mitochondria. This modified embryo is then implanted into the uterus and carried until childbirth, resulting in a baby free from the mother’s mitochondrial disease.
Potential Side Effects of MRT
Although this procedure has shown encouraging results, it is not without risks. In some instances, a small quantity of defective maternal mitochondria may be unintentionally passed on during the procedure. More research and published data are required to establish consensus and enhance the technique for better outcomes.
Legislation and Approval of MRT
The UK government updated its law in 2015 to allow mitochondrial replacement therapy, and the Newcastle Fertility Centre became the first licensed centre to perform this process in 2017.
Mitochondrial Disease Statistics
Globally, approximately 1 in 5,000 people suffer from a genetic mitochondrial disease. These disorders impact around one in 6,500 babies born in the UK, with approximately 12,000 people in the country living with these conditions. Conversely, in the United States, an estimated 1,000 to 4,000 babies with mitochondrial disease are born each year.