Brave New Cells?
LONDON – The United Kingdom’s Human Fertilization and Embryology Authority (HFEA) has launched a public consultation to gauge attitudes toward controversial new medical procedures aimed at preventing the transmission of incurable diseases that result from mutations of cell structures called mitochondria. Supporters of such research are framing criticism of it as opposition to saving children’s lives and an impediment to scientific development. But this view neglects a crucial factor in the debate: the techniques being developed involve permanent genetic alterations passed on to future generations.
The mitochondria are the energy-producing “batteries” of the cell, containing the only DNA outside of the cell nucleus – 37 genes, or roughly 0.2% of a person’s genetic makeup. Given that these genes are contained in the egg, and thus are inherited only from the mother, the new techniques aim to replace the mother’s mutated mitochondria with that of a healthy female donor of eggs without the mutation. This results in embryos that contain genetic material from three people – the child’s father and mother, plus the egg donor.
So the real question is how the public feels about crossing the line between medical treatments for existingpeople and irreversible genetic alterations that would be passed on to future generations through genetic modification of the human germline (the sequence of germ cells,such as sperm and eggs, containing genetic material that a child may inherit).