VANCOUVER—The United Kingdom may become the first country to count babies with three parents among its citizens.

Members of Parliament voted 382-128 Feb. 3 to allow the creation of embryos from the DNA of three parents, in order to prevent a certain genetic disease.

“For the many families affected, this is light at the end of a very dark tunnel,” said Health Minister Jane Ellison.

The procedure is intended to prevent an inheritable mitochondrial disease that is passed on by the mother and affects one in every 6,500 babies. It can lead to brain damage, muscle wasting, heart failure, and possibly death.

The three-parent technology is called “oocyte modification in assisted reproduction.” It uses in-vitro fertilization and takes the DNA from a mother and father and inserts them into an egg from a second “mother” who has healthy mitochondria.

The House of Lords still has to approve the bill before the first three-parent baby can be conceived. Doctors and ethicists are warning against what they call a “historic mistake.”

“Since this is uncharted territory, and the children born from this technology would have heritable genetic changes, there are also significant unknown risks to future generations,” said Paul Knoepfler, a cell biology professor at the University of California.

He added there is a possibility three-parent children will be stillborn or born disabled, be more susceptible later in life to cancer, and age more quickly than their peers.

David King, the director of Human Genetics Alert in London, has warned that this technique crosses an ethical line.

“It is a disaster that the decision to cross the line that will eventually lead to a eugenic designer baby market should be taken on the basis of an utterly biased and inadequate consultation,” he told the BBC.

Auxiliary Bishop John Francis Sherrington of Westminster has also spoken against the risky procedure.

“The human embryo is a new human life, and it should be respected and protected from the moment of conception,” he said. “This is a very serious step which parliament should not rush into taking.”