A US advisory board debated a controversial new technique Wednesday that would use DNA from three people to produce embryos free of a particular type of hereditary disease.
The panel, which provides independent advice to the US Food and Drug Administration, weighed whether a procedure that replaces part of a human egg cell with that of another is safe for clinical trials. Supporters of “three-parent in vitro fertilization” point to the technique’s huge medical potential, while detractors say it could lead to custom-made “designer babies.” It has only been tested on monkey embryos so far.
The panel’s chairman, Evan Snyder, suggested the time may not be right to proceed to human trials.
“There is overall a great concern for the well-being of these kids,” he said at the meeting, according to participants. “I think there was a sense of the committee that at this particular point in time, there was probably not enough data either in animals or in vitro to conclusively move on to human trials.” The panel did not conduct a vote, according to a Food and Drug Administration spokeswoman.
At the center of debate lie mitochondria, a structure where most of a cell’s energy is created, that also contains DNA separate from the 23 chromosomes in a cell’s nucleus. Each year, some 1,000 to 4,000 children born in the United States develop mitochondrial diseases, which often affect the central nervous system, or cause blindness or heart problems.
The diseases, which generally become evident before age 10, often result from genetic abnormalities in mitochondria, which are passed down from a child’s mother.
Under the procedure, a disease-producing mitochondria in an egg is replaced with another woman’s mitochondria, before the egg is then fertilized in a laboratory and implanted in the mother.
Shoukhrat Mitalipov, the scientist at Oregon Health and Science University who created the procedure, successfully oversaw the birth of five monkeys using the technique.
He would now like to pursue clinical trials on humans.
In 2001, using a different technique, US scientists carried out successful three-parent fertilization experiments that resulted in the birth of some 20 children. But the FDA asked them to halt the procedure on humans. The Center for Genetics and Society lobby group launched a petition against approval of Mitalipov’s “biologically extreme procedure.” But director Marcy Darnovsky struck a conciliatory tone after the meeting.
“It was reassuring to hear how seriously most of the FDA committee members take the many significant concerns about the safety of the proposed procedures,” she told AFP.
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