© JENNY NICHOLS, WELLCOME IMAGESIn 2015, the US Congress banned the use of gene-editing techniques, such as CRISPR, for the creation of genetically modified human embryos. President Obama also signed into law a policy that precludes modification of the human germline. An unresolved issue with Congress’s ban and President Obama’s law is whether they encompass mitochondrial replacement therapy (MRT), a procedure that allows women with mitochondrial disease to give birth to unaffected children by inserting a nucleus from one of her eggs into an enucleated egg from a woman with healthy mitochondria, followed by in vitro fertilization.
A recent National Academies of Sciences, Engineering, and Medicine report stated that MRT is ethical if conducted exclusively in male embryos and limited to women with mitochondrial diseases. And recent studies have shown that mitochondrial donation has broader clinical applications beyond treating mitochondrial diseases, specifically in relation to infertility problems typically suffered by older females. In 2015, for example, a private research enterprise made headlines when its scientists revitalized senescent eggs through MRT before fertilizing them in vitro, helping an infertile couple in Canada give birth to a healthy baby boy. These expanded indications for MRT only strengthen the rationale for its use as an approved form of germline intervention.
Mitochondrial replacement therapy will probably emerge as an effective method to enable women with mitochondrial ...
