The UK looks set to become the first country to allow the creation of babies using DNA from three people, after the government backed the IVF technique which involves replacing maternal faulty mitochondria with those of another woman.
Many say three-person IVF could eliminate debilitating and potentially fatal mitochondrial diseases that are passed on from mother to child.Opponents say it is unethical and could set the UK on a “slippery slope” as it is the first treatment that will permanently alter genes and involves a change in the germ line [inheritable DNA] .
Mitochondria, as all of those studying biology know are the ‘batteries’ of the cell providing the majority of energy from respiration. When mitochondria become faulty there are a range of problems from muscle weakness, heart disease and early dementia. About 1 in 200 babies born will have mitochondrial disorders. Doctors have tried to rectify these by injecting donor mitochondria into faulty cells but this has not been successful as they are so small and easily damaged.
Mitochondria are probably the remnants of a symbiotic relationship with bacteria. They were probably bacteria that were engulfed by cells; these cells then had a massive evolutionary advantage being able to generate 15 times as much ATP [the energy currency of a cell]. Mitochondria are the same size as bacteria, also contain circular DNA, have bacterial type ribosomes and enzymes and have a double membrane like bacteria.
Mitochondria are outside the nucleus and are not involved in fertilisation of the sperm and egg nuclei. Mitochondria are solely inherited from the mother – the egg cell mitochondria present in the cytoplasm will form the foetal mitochondria. Doctors have recently developed techniques to prevent mothers passing on mitochondrial diseases to their children. In this new technique the nucleus from a fertilised egg cell will be placed into a donor egg cell with normal mitochondria that has had its nucleus removed. The nucleus will contain genetic information from the parents – mother and father and the enucleated egg cell [egg cell without a nucleus] from a third person. The newly formed embryo will thus have genetic information from the original two parents and genetic mitochondrial information from the donor –‘three parents.’ This will cause a genetic change in the mitochondria which will be passed down the line to other generations.
This affects what the HFEA describes as the germ line. Tampering with germ line is illegal and to many conjures up the spectre of eugenics and slippery slopes which lead to ‘designer babies‘. It requires a change in the law to make it legal. HFEA [the Human Fertilisation and Embryology Authority] have involved the public in consultation which has has been generally in favour of a change in the law. Draft proposals are being prepared and it may be offered within the next two years!
http://www.bbc.co.uk/news/magazine-19648992 Click on the link to read about the parent who lost 7 children to this disorder.