An historic vote in the House of Commons yesterday on the Human Fertilisation and Embryology (Mitochondrial Donation) Regulations 2015, passed by 382 votes to 128

Alliance MP Naomi Long was the only Northern Ireland politician to vote in favour of changing legislation so a baby can be created with DNA from two women and one man.

An historic vote in the House of Commons yesterday on the Human Fertilisation and Embryology (Mitochondrial Donation) Regulations 2015, passed by 382 votes to 128.

The regulations would allow biological material from three people to be used in the creation of an embryo, to prevent the transmission of mitochondrial disease, which is passed down from women only and can lead to blindness, brain damage, heart failure and muscle wasting.

SDLP MPs Margaret Ritchie and Mark Durkan voted against, as did Independent MP Lady Hermon and all DUP MPs, except for Nigel Dodds, Ian Paisley jnr and David Simpson, who were absent from the Westminster vote.

SDLP leader Dr Alisdair McDonnell was also absent. The House of Lords votes next on the regulations, which would apply UK-wide.

The proposed modified version of IVF would combine DNA from a man and a woman, with the healthy mitochondria of a donor woman.

It results in babies with 0.1% of their DNA from the second woman and is a permanent change that would be passed down through generations.

Ms Long said it was "not a slippery slope for other genetic treatments".

"While it is likely to be a number of years before these techniques will be ready for trials in a clinical setting, it is incredibly promising they could result in a treatment which would allow women with mitochondrial disease to give birth to healthy children, who are free of a fatal disease," she said.

The Human Fertilisation and Embryology Authority recommended the UK Government back mitochondria replacement and said ethical concerns were outweighed by arguments in favour of permitting the techniques.

Lady Hermon voted against as scientists "have not tested the long-term consequences".

Snd DUP MP Sammy Wilson said it was "a change in a medical procedure for which there has been very little medical research", claiming the procedure is "genetic modification and we don't yet know the full range of effects that this can have on a person's characteristics and traits".

Factfile

Defective mitochondria leads to blindness, brain damage, heart failure and muscle wasting. The proposed technique uses a modified version of IVF to combine DNA of two parents with healthy mitochondria of a donor woman. It results in babies with a small percentage of their DNA from the second woman and prevents the disease being passed on.

So, what is mitochondrial donation?

MPs yesterday decided that mitochondrial donation allowing IVF babies to be born with DNA from three different people should be legal. The technique involves replacing DNA in an egg to prevent devastating inherited mitochondrial diseases.

Q. What are mitochondria?

A. Mitochondria are tiny rod-like structures in cells which act as power houses, generating the energy that allows our bodies to function. Unusually, they have their own DNA, distinct from the genetic material within the cell nucleus. Mitochondrial DNA (mDNA) makes up about 0.1% of a cell’s total DNA and does not affect individual characteristics such as appearance and personality.

Q. What causes mitochondrial disease?

A. Harmful mutations in mitochondrial DNA can prevent the mitochondria working properly, resulting in a number of diseases, some of which can be serious and life threatening. They may affect major organs and cause conditions ranging from poor vision to diabetes and muscle wasting.

Q. How are mitochondrial diseases passed on?

A. Children may inherit mitochondrial DNA defects from their mothers, but not their fathers. People with faulty mDNA can develop symptoms or carry the condition without having ill-effects themselves.

Q. What is mitochondrial donation?

A. Defective mDNA from a mother’s egg can be replaced with healthy mDNA from a donor. This will then prevent the harmful mutations being inherited and passed on to future generations.

Q. What are the techniques involved?

A. There are two different procedures, one carried out before fertilisation and the other after.

Maternal Spindle Transfer (MST) involves first removing the nuclear DNA from a donor egg whose mitochondria are healthy. The “spindle” of chromosomes containing the mother’s nuclear DNA is then taken from her egg and inserted into the donor egg. The donor egg is then left with nuclear DNA from the mother and mDNA from the donor. This healthy egg is fertilised and implanted into the mother’s womb.

Pronuclear Transfer (PT) is similar but in this case the mother’s egg is fertilised first. Its nuclear DNA is transferred to a fertilised donor egg, containing healthy mitochondria, whose own nuclear DNA has been removed. This healthy fertilised egg is then implanted.

Q. How safe is mitochondrial donation?

A. Animal and laboratory experiments suggest that the procedures are safe, but no-one can say the risk is zero. Three separate reviews by an expert panel convened by the Human Fertilisation and Embryology’s Authority have found no evidence that the techniques are unsafe for clinical use.

Critics argue that problems might only arise once the procedure is used to create human babies. For instance, replacing mDNA might have more of an impact on personal traits than had been envisaged. Unknown epigenetic effects, environmental influences that alter the way genes work, may also have serious consequences for the health of babies, it is claimed.

Belfast Telegraph