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Three parents, 1 baby: Three parents baby
What is a three-parent baby?
A “three-parent baby” is born after faulty bits of the mother’s DNA are replaced by those taken from a healthy donor. The DNA thus replaced is the mitochondrial DNA that a baby inherits entirely from its mother. Last week, the UK overcame serious ethical and medical concerns to become the first country to legalise three-parent babies after its fertility regulator, Human Fertilisation and Embryology Authority (HFEA) had approved the process. This decision was taken 2 weeks after an independent expert scientific panel convened by HFEA published its fourth review of the safety and efficacy of mitochondrial donation. The panel recommended that the technique could be used cautiously for risk reduction treatments in certain cases where alternative treatments would be of little or no benefit to mothers at risk of passing mitochondrial disease on to their children, according to the HFEA statement. In September, a three-parent baby was born in Mexico, but the process has no legal sanctity there.
Concepts related with it:
Mitochondria are double-membraned cellular organelle, which are crucial for generating energy. They are commonly known as the powerhouse of the cell, but what really makes them unique is that they divide independently of the cell. They have a very small genome of their own, which in many ways resemble that of more primitive life forms. The mitochondrial DNA controls its functions much like the rest of the DNA (what is known as the nuclear DNA after the fact that it is lodged in the nucleus of the cell) of any living form, and decides what the organism would look and act like. It makes up less than 0.0005% of our entire DNA, but since the child receives it only from the mother, any aberrations in her mitochondrial DNA that may cause diseases is passed on completely to the child.
How often are children born with diseases inherited from faulty maternal mitochondrial DNA?
According to the New York Stem Cell Foundation Research Institute, approximately 1 in 5,000-10,000 children are born each year with mitochondrial disease. “These can be devastating diseases, with symptoms often arising in childhood. Symptoms can include stunted development, neurological disorders, heart disorders and stomach and digestive problems, among others, and can result in childhood death. There are no cures to these diseases-only symptom management.” Figures for India, or whether they apply to this population, are not clear. Some diseases where aberrations in the mitochondrial DNA may have a role to play, include, according to evidence that is still evolving, Alzheimer’s, Parkinson’s, and Type II diabetes.
What is mitochondrial replacement therapy?
The errant mitochondrial DNA may be removed either before or after in-vitro fertilisation. In the first case, the nuclear DNA of the donor egg is removed and replaced by that of the egg from the woman whose mitochondrial DNA needs to be replaced. After that this egg is fertilised as usual and implanted into the womb. In the second option, following in-vitro fertilisation, the fertilised nuclear DNA is transferred to a donor egg from which the nuclear DNA has already been removed. This leaves the errant mitochondrial DNA out as the fertilised nuclear DNA now has the donor mitochondrial DNA for company.