Researchers say devastating birth defects caused by tiny genetic errors in a mother’s DNA could be prevented with a controversial procedure that would produce an embryo from the recombined DNA of a mother, a father and a second female donor. The in-vitro fertilization technique, known as 3-parent IVF, would correct the mother's defective egg with the healthy genetic material from a female donor. The experimental procedure is stirring a big debate in Britain, where medical researchers are hoping to win government approval for human trials.
Three-parent IVF involves producing embryos for implantation in the womb that contain the genetic material of three individuals - two women and a man. It is designed to correct mitochondrial diseases - inherited conditions passed down through the mother's DNA. Mitochondria are the biochemical power plants in every human cell. When they don't function properly, the result is a wide range of mostly neuromuscular problems, some of them devastating. But they also can affect the heart, and cause vision and hearing loss, seizures and serious digestive problems.
To correct the mitochondrial glitch, doctors say they would fertilize the mother’s defective egg with the father’s sperm, and then transfer their genetic material into a hollowed-out egg containing a female donor's healthy mitochondrial DNA. The corrected egg then would be implanted into the mother to carry to term, permanently eliminating the risk of mitochondrial disorders from the family line. That's the theory, anyway.