Although the first human birth using mitochondrial replacement techniques (MRT) has been called a success story in recent headlines, Lainie Friedman Ross, M.D., Ph.D., FAAP, urged a cautious approach that takes ethics and evidence into consideration as she presented Monday’s plenary “Who's Your Mommy? Who's Your Daddy? Bioethics of Reproductive Technology.”
A “three-parent embryo,” as it is being called by mainstream media, results in a baby who is conceived with genetic material from one man and two women. The technique helps mothers who might be genetically predisposed to conceive children with fatal genetic diseases.
“It’s going to be really hard to convince the rest of the scientific community to proceed with caution, although that’s something I think we really should be doing,” said Dr. Friedman Ross, Carolyn and Matthew Bucksbaum Professor of Clinical Ethics, University of Chicago. “We are not going to know how it’s going to work in humans until we have use in humans.”
In April, the first child with MRT was born to Jordanian parents in Mexico after the loss of two siblings to Leigh syndrome.
Though celebrated in the media, mitochondrial replacement techniques are not safe, said Lainie Friedman Ross, M.D., Ph.D., FAAP, who outlined risks to the mother and child-to-be.Dr. Friedman Ross, a member of the AAP Section on Bioethics and past member of the Committee on Bioethics, explained the history behind the current U.S. position on MRT safety, which takes a new report into advisement. The Food and Drug Administration charged the National Academies of Science, Engineering and Medicine to convene a committee and develop a report examining the ethical and social policy considerations of novel techniques for prevention of maternal transmission of mitochondrial DNA diseases (http://bit.ly/2e4mQSV). The report says that conducting clinical investigations of MRT in humans is ethically permissible as long as significant conditions and principles are met.
“MRT is not unsafe,” Dr. Friedman Ross said. Women face risks of failure to become or stay pregnant, are exposed to toxicities of reagents used, and could have complications from egg donation procedures. The benefit, however, is a healthy child who is genetically related.
The child-to-be faces risks of mitochondrial disease carryover, birth defects and potential risk of developing disorders observed in animal studies, noted Dr. Friedman Ross.
She cited ethical concerns, including “playing God.” Other concerns involve eugenics and attitudes toward disabilities and unequal access. As countries move forward with MRT, legislation will need to be changed. Practically all countries prohibit or discourage germline manipulation.
The current position in the U.S. differs from the U.K., which in 2015 moved to permit the creation of embryos with donations from three individuals. The process involved changing the definition of the germline to refer only to genetic material that is inheritable. The U.K. also distinguishes between nuclear and cytoplasmic DNA and clarifies germline manipulation and substitution.
In the future, MRT could be expanded for cases of infertility, enhancement for traits such as exercise performance and aerobic capacity, and to thwart the consequences of aging, she said.
“Clearly, we’re going to need long-term follow-up for the children, and an international registry would be ideal,” she said. “We are going to need to follow (MRT) not just for months but for years and decades.”
