Wide support in UK for novel DNA 'transplants' in human egg cells

Technique to prevent inheritance of disease-causing mitochondria moves closer to clinic.

The United Kingdom moved a step closer to legalizing reproductive gene therapy techniques that could prevent children from inheriting certain genetic diseases caused by faulty mitochondria, the cell’s energy producing structures.

The Human Fertilisation and Embryology Authority (HFEA) today voted to advise the government on the regulation of the techniques, which are meant to prevent the inheritance of mitochondria — which carry DNA outside the ordinary chromosomes in the nucleus — from mothers whose nuclear DNA is healthy. The procedures involve transferring the nucleus of an egg cell with diseased mitochondria to a healthy donor cell.

The HFEA decision follows a public consultation on the science and ethics of the procedures, which was launched last September. The government must next decide whether to write legislation to legalize the procedures. Parliament would then need to pass the law. The HFEA would likely get the final say before the first procedures go forward. No other country has legalized the procedures, which combine in vitro fertilization with the egg cell swaps.

“We’ve done our work, now the work of the government begins,” said HFEA chair Lisa Jardine after a meeting to consider the public consultation in which no HFEA members raised significant objections to moving ahead. Their consultation involved public meetings, focus groups, questionnaires and other outreach. It found broad public support for allowing the procedures, when used to prevent serious diseases.

Approximately one in 5,000 women carry mutations in their mitochondria that put their children at risk of inheriting mitochondrial diseases, including forms of muscular dystrophy and diabetes. The two techniques being investigated — maternal spindle transfer (MST) and pronuclear transfer (PNT) — have been tested in animals, including mice and macaques, and in human cells...

Any Dr's here who can give a layman's response on how far to the moral edge this goes...?

Mitochondria get their DNA just from the mother. Attempts at gene therapy haven't been very successful. Most have used viral vectors to piggy-back the genes into the patients' cells and then into the nucleus. The target here is the mitochondria precursor of an unfertilized ovum. I can't think of another way of doing it.

I'd like to hear what the Vatican has to say. Pope Francis has a master's degree in chemistry. I'm pretty sure he can deal with the science. They're might not be a problem if fertilized eggs are not discarded or just be used for research, i.e. all carried to term.

Not a DR, but 20+ years a biotech analyst who had to write about this every so often. The ethical collapse is the surrender to the unknown in the interest of a superficial perception of medical benefit.

The lack of objections of the “experts” is likely driven by a whole bunch of extraneous factors. Political pressure, undisclosed financial interests, being stuck on stupid over certain “value-laden” beliefs that favor throwing caution to the wind, and other factors some more thought could identify.

Messing with mitochondria is a funny one. Technically, you are not messing with the actual germ line of an individual. Mitochondrial DNA are separate from human DNA. It has it’s own time phase for replication, also separate from the time phase for mitosis.

Does it follow that messing with mitochondria messes with the germ line? At first blush, the answer would appear to be no. BUT, and this is a BIG BUT, mitochondria also control cell death known as apoptosis. I would like to hear from these folks on how they are certain they are not screwing with the many and complex mechanisms of apoptosis in an attempt to “correct” mitochondrial dysfunctions.

I don’t know what a normal mitochondria is. How much genetic variation is there in mitochondria without “dysfunction”. There are some clear lines separating some genetic functions from others, but it is fair to say we need a lot more knowledge.

Another area I would like to understand better is the relationships between RNA and mitochondria. The wacky world of epigenetic (control of genetic traits by RNA) is becoming increasingly prominent.

The bottom line is that not nearly enough work has been done to identify possible damage done to people with these proposed techniques for modifying mitochondria. They also control important phases of steroid hormone creation in the body. As far as I’m concerned it is irresponsible to not start doing the cross connections between these different areas and answer important questions. That is the ethical collapse.

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