British lawmakers have voted to approve "three-person babies" created from DNA of two women and one man in a technique intended to keep genetic diseases from being passed down from mother to child.
The House of Commons voted 382 to 128 to approve the use of the procedure, paving the way for Britain to become the first country in the world to introduce laws allowing the procedure.
If approved by the House of Lords, a first attempt at creating a three-parent baby could take place later this year.
The technique, developed be the University of Newcastle, aims to avoid diseases caused by mutations in mitochondrial DNA, passed down to children from their mother.
Such mutations can result in brain damage, blindness or heart failure in addition to other ailments. As many as one in 5,000 people are believed to suffer from some form of mitochondrial disease.
The "three-parent" technique utilizes a modified version of in vitro fertilization to join the DNA of the mother and father with the healthy mitochondria of a donor woman.
Babies born of this procedure would have 0.1 percent of their DNA from the donor.
There was considerable debate from both sides of the Commons before the vote.
"This is a bold step for parliament to take, but it is a considered and informed step," said Public Health Minister Jane Ellison.
"And for the many families affected, this is light at the end of a very dark tunnel."
Other MPs expressed worry over the fact that the donor DNA represents a permanent genetic change that will be passed down to succeeding generations.
"[This] will be passed down generations, the implications of this simply cannot be predicted," MP Fiona Bruce said.
"But one thing is for sure, once this alteration has taken place, as someone has said, once the gene is out of the bottle, once these procedures that we're asked to authorize today go ahead, there will be no going back for society," she said.
Although both the Catholic and Anglican churches had expressed opposition to the procedure, and some groups warned it could open the door to so-called designer babies, the vote was greeted with approval by many in the scientific community.
"We have finally reached a milestone in giving women an invaluable choice, the choice to become a mother without fear of passing on a lifetime under the shadow of mitochondrial disease to their child," said Robert Meadowcroft, chief executive of Britain's Muscular Dystrophy Campaign.
