Researchers in the United Kingdom may now apply for licenses to conduct mitochondrial replacement therapy clinical trials on a limited basis (1).  If successful these techniques will produce‘3-parent’ babies with genetic contributions from three sources.  The complex strategy to move maternal DNA into eunucleated donor eggs with healthy mitochondria offers some prospective parents the opportunity to avoid passing potentially lethal genetic defects to their children.




Three-parent babies have already been created in locations that had no laws against such protocols at the time (1, 2). Although the technique has apparently been successful, it will take time to be sure because the methods employed cannot totally eliminate all defective mitochondria which may outcompete healthy forms (1).  There is reason for optimism, however, clinical trials in the United Kingdom will be managed carefully.    

For the time being United States researchers interested in moving the new technologies into the clinic will need to conduct their work elsewhere.  Congress has effectively prevented any the Food and Drug Administration from reviewing any proposals to use the 3-parent methods in human subjects (3).  It is unclear if reservations regarding using these methods are resolvable through political means.  Whether a projected re-purposing of mitochondrial replacement therapy to infertility treatment option (4) will aid public acceptance or inflame concerns is likewise uncertain.

Dr. George Church, a leader in genomic research technology development, has argued forcefully that pursuing some controversial areas of research is preferable to abandoning them to biotech opportunists (5).  The static situation in the U. S. has already induced one group to take their 3-parent baby expertise to less restrictive jurisdictions (2).  Perhaps the limited approval of mitochondrial replacement therapy research in the U. K. will encourage others to follow that example.  Past experience with stem cell therapies suggests that the prospect of paying customers can drive the creation of an industry (6).  Biomedical entrepreneurs seeking primarily to satisfy market demand may consider limitations and prohibitions to be signals to move on to greener pastures.  In the long term haste to earn a profit may be to the detriment of both good research practices and the bill paying public.    


(1) E. Callaway. 2016.  Historic Decision Allows U.K. Researchers to Trial ‘Three Person’ Babies.  Nature, 15 December 2016.

(2) S. Reardon. Nature, 28 September 2016.

(3) G. Vogel. 2016.  United Kingdom Gives Green Light for Mitochondrial Replacement Technique.  Science, 15 December 2016.

(4) A. Coghlan, New Scientist, 10 October 2016.

(5) G. Church. Encourage the Innovators.  Nature, 3 December 2015.

(6) L. Beil. 2013.  Stem Cell Treatments Overtake Science.  The New York Times, 9 September 2013.