Thanks to a US medical team and an auxiliary mother, a Jordanian couple have had a child in Mexico. It is a story of our globalised times, and of the triumph of science over incurable genetic disease. The couple chose the frontline genetic technology, which is banned in almost all scientifically competent countries, after losing two children to a defective mitochondrial gene. Mitochondrial DNA is transmitted by the mother, while nuclear DNA is transmitted through both parents. The solution was to inject a healthy nucleus, with both parents’ DNA, into an enucleated egg carrying the auxiliary mother’s mitochondria.
Three-parent children have been eagerly anticipated though the ethics involved are hotly debated. There are concerns about using human embryos, paying for germplasm and altering transmissible germlines with unknown results. Besides, can babies created by such interventions belong in the traditional family system? John Zhang of New York’s New Hope Fertility Centre, whose team created the three-parent baby, has brushed these anxieties aside, saying that saving lives is the only ethical principle which ought to matter.
In this case, the child is male while mitochondrial DNA is transmitted through women, and the end of the line is clearly marked. But such research does lead to a slippery slope, since mitochondrial DNA is believed to influence aging. Procedures designed to bring compromised humans up to the norm of good health can be taken to their logical conclusion, to deliver enhancements beyond the norm. In this case, the objective would be the fountain of youth, whose market value is simply incredible. And genetic enhancements to the mind and body would make current anxieties about cheating in examinations and doping in sport absolutely laughable. Genetic manipulation is inevitable, but the question is whether researchers can draw the line as clearly as Zhang has done.