Mitochondria are the powerhouses of cells. The adaptation of in vitro fertilization technology is likened to replacing the mitochondrial DNA "battery" in a laptop.

The techniques are currently used in labs in Britain and the U.S., but the modified embryos haven't been implanted into women.

When faulty mitochondria are inherited from a woman, diseases such as muscular dystrophy, epilepsy and heart problems can result with varying degrees of severity. The diseases affect round one in 6,500 children worldwide.

"Scientists have developed ground-breaking new procedures which could stop these diseases being passed on, bringing hope to many families seeking to prevent their children inheriting them," Sally Davies, U.K.’s chief medical officer, told reporters.

"It's only right that we look to introduce this life-saving treatment as soon as we can."

Any final decision on putting the regulations in place to allow the new treatments will be subject to a vote in Parliament. Davies hopes the first patients will receive the treatment within two years.

Under Canada's Assisted Human Reproduction Act, it's illegal to knowingly "alter the genome of a cell of a human being or in vitro embryo such that the alteration is capable of being transmitted to descendants."

For Tim Caulfield, Canada Research Chair in Health Law & Policy at the University of Alberta in Edmonton, if the technique is shown to be safe and effective, then it seems ethically appropriate.

"While it is unclear how the law would be interpreted, some may believe the technique infringes several of our bans," Caulfield said in an email.

The Canadian Fertility and Andrology Society represents doctors and researchers working on assisted reproductive technologies.

The group's president, Dr. Matt Gysler, who practises in Mississauga, Ont., cautioned the technology isn't ready for day-to-day use by responsible physicians in Canada.

"Looks to me, like in Britain, very responsible steps are taken before it is widely opened, so it can develop in a safe environment and protect the unborn and protect society and give mothers appropriate options and choices."

One of the main concerns raised during public consultations by Britain's Human Fertilization and Embryology Authority was designer babies.

"Once you have crossed that crucial ethical line of not manipulating genetically human beings, then it is very hard to go back and avoid slipping down that slippery slope," said Dr. David King, director of Human Genetics Alert, a London-based watchdog group that opposes genetic discrimination.

Françoise Baylis, who holds the Canada Research Chair in Bioethics and Philosophy at Dalhousie University in Halifax, pointed out that there is more than one way to be a parent.

"I would say that unless you're deeply committed to … belief that biology is what matters in making families, there are other ways of having a child and having a family that don't require the investment of time, talent, energy, money to allow five to 10 people a year to have a child that's genetically related to them," said Baylis.

"These women could easily use donor eggs and in fact that's what happens with a number of other underlying genetic conditions."