This Jordanian newborn represents the first successful birth in a new wave of "three parent" techniques — ones that are more sophisticated and that will likely stick around much longer.
For now, there is no country where the method used to conceive the baby boy is explicitly legal. Zhang performed the procedure in Mexico, where, he told New Scientist, "there are no rules."
These techniques involve the transfer of mitochondrial DNA or mtDNA. Often called the "power plants" of the cell, the mitochondria convert energy from food into energy that can power a cell. When someone's mitochondria don't function properly, it's bad news indeed for cells. Mitochondrial diseases can cause a whole host of life-threatening problems, and it's estimated that as many as 4,000 children are born with such conditions in the United States each year. In this case, the couple had experienced four miscarriages and lost two children at young ages to Leigh syndrome, a neurological disorder caused by a mutation in the mother's mitochondrial DNA.
Mitochondrial DNA, which contains just 37 genes compared to the staggering 20,000 or so carried by DNA in a cell's nucleus, comes entirely from the egg cell — the sperm cell contributes no mitochondria to the fertilized embryo, so there's no chance of a father's healthy genes picking up the slack after conception. Replacing the mother's faulty mitochondria with donor mitochondria in the newly conceived embryonic cells can produce a healthy baby while preserving the vast majority of its mother's DNA.
The United Kingdom recently approved a technique where two eggs (one from the mother and one from a donor) are fertilized with the father's sperm. The parents' genetic information is inserted into the donor's embryo, which has had everything but the mitochondria cleared out.
The baby seems to be healthy, New Scientist reports, but don't expect kids with 2.001 parents to become mainstream just yet: The baby was one of five embryos created for his parents using the technique, and he was the only one to develop normally after fertilization. He also still carries a small percentage of mitochondria with his mother's genetic mutation. His doctors hope and expect that he will develop normally, but there's no way of knowing how the presence of those malfunctioning genes might affect his health.