Stefani Bush, a 35-year-old mother, spoke to reporters from her bed, wrapped in blankets, because she cannot regulate her body temperature. She cannot walk more than 20 yards, and has a host of gastrointestinal and cardiovascular problems. This year alone, she has been to the hospital 16 times. Her symptoms come from a mutation in her mitochondrial DNA. Though Bush was unaware about her condition until seven years ago, her 9-year-old son has already been diagnosed with the same mutation. On a recent dream family vacation to Disney World, her now seven-year-old daughter spent an entire day suffering from seizures.
Bush, and perhaps both of her children, is among the 1,000 to 4,000 people in the United States who were born with mitochondrial mutations. Mitochondrial DNA, which is passed down from the mother, does not compose most of a person's DNA, nor is it responsible for a child's appearance or most of his or her characteristics, but it is incredibly important. Mitochondria are present in every cell in a person's body except blood cells, and are responsible for converting glucose into energy. And mutations in the 13 genes that mitochondria hold can cause rare diseases, with serious symptoms like blindness, deafness, dementia, epilepsy, heart disease, kidney failure, and strokes.
Now, recent research published in the journal Nature seeks to nip that problem in the bud with an unusual solution - three parents. There are two techniques that have been performed with experiments: one takes the chromosomes from the mother's egg, which contain 99.8 percent of the mother's genetic information, and places them in an egg where the chromosomes have been removed but the mitochondria are still there. That egg would then be fertilized by the father's sperm. The other technique would fertilize the mother's egg with the father's sperm before placing the product's nucleus in a donor egg of which the nucleus had been removed. The study published in Nature looks at the first proposed solution. Either way, the resulting child would barely have three parents; the parents would provide 99.8 percent of their DNA, and none of the DNA that dictates eye color or height. But the child would ostensibly be free of mitochondrial diseases.
The first technique, published in Nature by researchers at the University of Oregon, saw that embryos created from their technique were fertilized at the same rate as the control group. However, half were abnormal. Still, the results are encouraging; those that were normal developed to the blastocyst stage, five or days after fertilization when the eggs would normally be implanted in mothers, at a similar rate to the control group. Scientists are unsure about whether the embryos would lead to a healthy infant, and they want to conduct more studies to be sure that the procedure is safe. Previous studies on similar procedures on rhesus monkeys three years ago have produced juvenile primates that are indistinguishable from their peers.
The United Kingdom's Human Fertilization and Embryology Authority is mulling over a change in law that would allow three-parent in vitro fertilization to occur. The concern is whether the procedure would lead to a "slippery slope" of parents choosing designer babies with specific hair and eye colors.
But for Stefani Bush, the answer is clear. She said to NBC News that, if the option had been available to her and she had known about her condition, she would have done it. "If I could have spared my children one ounce of what they have gone though, I would," she said.