382 parliamentarians in the House of Commons voted in favor of what is known in Britain as the "three-person baby," 128 voted against the legalization. At present, the procedure is banned in the United States. If the British House of Lords also votes in favor, it would make Britain the first nation in Europe where the creation of babies with DNA from two women and one man could become legal.

For the past 15 years, a team of researchers at Newcastle University in Great Britain has been jumping over scientific and social hurdles to prevent the genetic transmission of mitochondrial disease, a debilitating condition that can lead to a range of organ and muscular deficiencies comprising heart failure, neurodegenerative disease, diabetes, dystrophy and an array of different cancers.

This is how their "three-parent-baby" method works:

A woman who suffers from mitochondrial disease and who desires children provides her genetic material, isolated from one single cell in a laboratory. A second woman without mitochondrial disease donates an egg cell, which has its core, or nucleas, removed. The only genetic material contained in the second cell comes from the mitochondria.

The nucleus from the first egg cell is "transferred" into the second egg cell, and the second cell is then fertilized by a sperm cell of the desired father. The resulting embryo is implanted in the uterus of the first woman, as with any instance of standard in vitro fertilization (IVF).

'All - and only - about energy'

"The sole aim of our research has been to help fix the way cellular batteries [mitochondria], if you will, work in the children of mothers with similarly damaged cellular batteries - no more, no less," said Doug Turnbull, of Newcastle University, who has pioneered research in the practice known as "pronuclear transfer."

The vast majority of a human being's genetic makeup is determined by chromosomes, located in the core of every cell, or the nucleus; however, a small fraction of human DNA is stored in the mitochondria, which only mothers can pass on to their children.

"The only thing, genetically, passed on by a mother's mitochondria pertains to mitochondria," Turnbull explained to DW, adding that when damaged mitochondrial DNA was passed on to any child disastrous consequences could ensue.

"We've been treating patients with mitochondrial disease here [in Newcastle] for decades, and their suffering is great. Muscles, heart, brain, you name it. Every human cell needs energy, and when there is a problem in providing that energy other severe problems will emerge."

Despite the immense energy that Turnbull and his Newcastle team have put into developing the practice of pronuclear transfer, in essence, the procedure is as simple as a transfusion, one of Turnbull's colleagues told British media ahead of Tuesday's parliamentary vote.

"Transfusing mitochondria is not unlike transfusing red blood cells in a case of severe anemia," Robert Winston, fertility expert at Imperial College London, told the daily Telegraph on Monday. "As an orthodox Jew, my religious tradition sees no objection to using science in this way," Winston said.

"If mitochondrial treatments could prevent disease, this is to be celebrated as we are using the God-given intelligence afforded us."

Playing God?

The concept of the divine, meanwhile, in connection with mitochondrial genetics has provided the impetus for much criticism of pronuclear transfer. The Church of England and the Catholic Church in Britain have both cited "a lack of scientific proof" that mitochondrial replacement won't alter the child genetically.

Brendan McCarthy, the Church of England’s national adviser on medical ethics, called for "further scientific study and informed debate into the ethics, safety and efficacy of mitochondrial replacement therapy."

Bishop John Sherrington, of the Catholic Church, referred to the unprecedented nature of the amendment in his reservation: "No other country has allowed this procedure, and the international scientific community is not convinced that the procedure is safe and effective."

In response to allegations that he and his team were attempting to play God, however, Professor Turnbull mentioned that his calling had "one purpose only:"

"All medicine should be about helping patients. That's it. Am I playing God? ... I don't know. To me, that doesn't even make any sense."