Successful birth after preimplantation genetic testing for rare mitochondrial DNA mutation m.10197G>A.

Here we report the first successful birth after preimplantation genetic testing for m.10197G>A mutation, a rare variant responsible for Leigh encephalopathy. Preimplantation genetic testing diagnosed the embryo with a mutant load of <5%, and transfer resulted in a live birth. The mutant load of embryos diagnosed in this case was skewed to the extremes. Skewed segregation patterns have been observed in common mutations, but this case suggests that the same phenomenon may be seen in this rare mutation.