In August 1996, at St. Barnabas Medical Center in Livingston, N.J., a 39-year-old mechanical engineer from Pittsburgh named Maureen Ott became pregnant. Ott had been trying for almost seven years to conceive a child through in vitro fertilization. Unwilling to give up, she submitted to an experimental procedure in which doctors extracted her eggs, slid a needle through their shiny coat and injected not only her husband’s sperm but also a small amount of cytoplasm from another woman’s egg. When the embryo was implanted in Ott’s womb, she became the first woman on record to be successfully impregnated using this procedure, which some say is the root of an exciting medical advance and others say is the beginning of the end of the human species.

The fresh cytoplasm that entered Ott’s eggs (researchers thought it might help promote proper fertilization and development) contained mitochondria: bean-shaped organelles that power our cells like batteries. But mitochondria also contain their own DNA, which meant that her child could possess the genetic material of three people. In fact, the 37 genes in mitochondrial DNA pass directly from a woman’s egg into every cell of her offspring, including his or her germ cells, the sperm or eggs that eventually produce the next generation — so if Ott had a girl and the donor mitochondria injected into Ott’s egg made it into the eggs of her daughter, they could be passed along to her children. This is known as crossing the germ line…In May 1997, she gave birth to a healthy baby girl…

Two months later, her doctors published her case in the journal Lancet; soon, at least seven other U.S. clinics were doing the injection. Because the amount of donor mitochondria added to Ott’s egg was small, it was unclear how much third-party DNA would be present in the cells of her daughter. Ott says her doctors ran tests and did not find any, but it has been found in two other children born from the procedure. Although IVF drugs and devices are regulated by the Food and Drug Administration, IVF procedures (like all medical procedures) are generally not. But what media outlets came to call “three-parent babies” compelled the agency to take action. In 2001, the FDA informed IVF clinics that using a third person’s cytoplasm — and the mtDNA therein — would require an Investigational New Drug application…

Now, more than a decade later, two research groups in the United States and one in Britain each believes it has nearly enough data to begin clinical trials for a new technique based on the transfer of mitochondria — only in this case, researchers want to pair the nuclear DNA of one egg with all the mitochondria of another. Their aim is not to cure infertility. Rather, they hope to prevent a variety of devastating diseases caused by mutations in mtDNA. The new technique, which they call mitochondrial-replacement therapy, is far more advanced than the cytoplasm injection — and the researchers have studied the procedure’s impact on animals and human cells up to a pivotal point: They have created what appear to be viable three-parent embryos. They have yet to implant one in a woman, though…

Is our fear of crossing the germ line causing us to block a technology that could improve people’s lives, and if so, is the fear itself a thing we should also be afraid of?

RTFA. I’ve barely introduced the topic. You can presume my personal opinion would not be acceptable to any flavor of the FDA. Crass politics aside – unlikely in the USA – science moves ahead in tiny conservative steps. Bodies like the FDA are more conservative than that.

Like I said. RTFA. Think about what you think.