Why the First Baby Born With 3 Genetic Parents is a Breakthrough in Modern Parenting

The world's first baby from a pioneer three-person fertility method has been born. Now five months old, the baby boy has DNA from three different people: father, mother and an additional donor.

According to a report from New Scientist, the conception and birth of the baby was made possible by John Zhang and his team at the New Hope Fertility Center in New York City. The couple approached him after previous efforts to get pregnant and give birth ended up unsuccessful; they've experienced four miscarriages and the deaths of two children at that point.

The problem stems from the boy's mother carrying genes for Leigh syndrome, which is a fatal condition affecting the developing nervous system. Genes for this disease are found in DNA in the mitochondria, and about a quarter of her mitochondria have this Leigh syndrome mutation. Although the mother was and continues to be healthy, their children suffered from the genes.

Meanwhile, Zhang was working on the three-person fertility technique to prevent mothers from passing on mitochondrial disease.

For this particular couple, he used what's called the spindle nuclear transfer, which had him removing the nucleus from one of the mother's eggs and transfering it into a donor's egg that has also had its nucleus removed.

With this method, the egg fertilized by the father's sperm would have the mother's nuclear DNA and the donor's mitochondrial DNA, and the baby theoretically wouldn't suffer from the Leigh syndrome in his mother's mitochondria. A separate fact sheet from New Science revealed that a bulk - around 20,000 - of human's genes are in the cell's nucleaus and only 37 are in the mitochondria.

This approach is different from the one legal in the U.K. called the pronuclear transfer. Since Zhang's approach hasn't been approved in the United States either, he performed it in Mexico saying, "To save lives is an ethical thing to do."

Five embryos were created by Zhang and his team, but only one was able to develop normally - now the five-month old baby boy of the happy couple. The baby just needs to be monitored to ensure his mitochondria -- currently just carrying 1 per cent of the deadly mutation; not enough to be dangerous - remains healthy and mutation-free.