The US Food and Drug Administration has instructed a New York doctor to stop marketing his mitochondrial transfer procedure, the Associated Press reports.
The approach, also known as mitochondrial replacement, relies on genetic material from three people: nuclear DNA from the mother and father and mitochondrial DNA from an egg donor. The approach could limit the chances that mitochondrial diseases are passed on.
The doctor, John Zhang of New Hope Fertility Center, used such an approach to treat a Jordanian couple — the mother was a Leigh syndrome carrier — to have a healthy baby boy last year. The Verge notes that Zhang's company, Darwin Life, calls the procedure the "first proven treatment for certain genetic disorders and a successful solution to age-related infertility" on its website.
However, the procedure is not approved in the US. According to the AP, Zhang told FDA that his companies wouldn't use the technology in the US without permission. "Despite that commitment, you continue to market MRT to prevent the transmission of mitochondrial disease and to treat infertility," FDA says in its letter.
The Verge notes that Zhang sought permission in 2016 from the agency to conduct a clinical investigation, but the agency cannot give it. It is prohibited by law from considering requests that modify embryos, it adds.
The agency also notes in the letter that Zhang's attempt to get around the law by sending the modified embryos to Mexico or elsewhere for implantation is also not allowed.
The UK has approved the use of mitochondrial transfer, but tightly regulates it.