WASHINGTON — Scientists have produced monkeys with genetic material from two mothers, an advance that could help women with some inherited diseases have healthy children but that raises safety, legal, ethical and social questions if attempted in people.
Using cloning-related techniques, researchers developed a way to replace most genes in eggs from one rhesus macaque monkey with those from another, fertilized the eggs with sperm, transferred the resulting embryos into animals’ wombs and produced four apparently healthy offspring.
The technique was developed for women who carry disorders caused by defects in a form of DNA passed from females to their children, and the researchers said they hoped work will eventually translate into therapies for people.
“We believe this technique can be applied pretty quickly to humans and believe it will work,” said Shoukhrat Mitalipov of the Oregon Health & Sciences University in Portland, who led the work published online Wednesday by the journal Nature.
Many scientists hailed the research as a technically impressive feat that could help many families rid themselves of a variety of disorders caused by defects in genetic material known as mitochondrial DNA.
But the work also raises a variety of potentially thorny ethical and legal issues, including creating offspring with DNA from two mothers and a father.
“With this, you have potentially three genetic parents,” said David Magnus, director of Stanford University’s Center for Biomedical Ethics. “This will create the potential for legal and social conflicts.”
If applied to people, the work would alter a family’s genes in a permanent way that would be passed on for generations, violating a long-standing taboo in altering the so-called “germline” because of the potential of unforeseen consequences. Some experts worry that germline genetic manipulation would stir a market in expensive elective genetic enhancements.
The researchers acknowledged the work might raise ethical questions but said those needed to be balanced against the potential benefits.
“We realize this is not just a simple form of gene therapy. This type of gene therapy involves replacing genes in the germline, which of course will be transmitted to next generations, which is a concern,” Mitalipov said. “However, we’re talking about patients and birth defects that cause terrible diseases due to these gene mutations. So the only way to prevent these birth defects is to replace these genes.”
Georgetown University bioethicist Cynthia Cohen noted that when the technique “is attempted in humans, some abnormal embryos are bound to result. If they are discarded, this will raise major ethical concerns for those who view human embryos as nascent human beings, and by some who do not.”
