A reproductive technology that taps three parents’ DNA as a way to eliminate hereditary diseases could reach clinical trials if the Food and Drug Administration gives the go-ahead.
Reproductive technologies that marry DNA from three individuals will receive a trial in the court of public opinion this week. Such technologies may hold promise for averting certain genetically inherited diseases passed down via mutations to mitochondria, the cell’s battery pack.
Scientists have already had successes with this type of reproductive approach in monkeys and in human embryos, and are now eager to launch human clinical trials. First, however, they must get the green light from the U.S. Food and Drug Administration, which will convene a public hearing before an advisory committee on February 25.
The technology, called oocyte modification (but sometimes nicknamed “three-parent IVF”), involves scooping out potentially mutated mitochondrial DNA (mtDNA) from a woman’s egg and replacing it with the mtDNA of an unaffected donor woman. The process is designed to prevent the transmission of some debilitating inherited mitochondrial diseases, which can result in vision loss, seizures and other maladies. Such inherited diseases, often unfortunately known by acronyms for complex medical names that include LHON, for Leber’s Hereditary Optic Neuropathy, along with MELAS, MERRF and NARP, occur in about one in every 5,000 live births and are incurable.
Once the mtDNA has been swapped out, the egg could be fertilized in the lab by the father’s sperm and the embryo would be implanted back into mom where pregnancy would proceed. The resulting child would be the genetic offspring of the intended mother but would carry healthy mitochondrial genes from the donor.
Although the mitochondrial genome is quite small, the genes themselves are avid reproducers, so that an individual cell contains hundreds or thousands of copies of its DNA. The mutation rate of mtDNA is much higher than that of nuclear DNA and such miscodes can cause severe damage to any part of the body.
Written By: Dina Fine Maron
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