Curing Mitochondrial Diseases and Repudiating this "3-Parent-Baby" Nonsense

    20/06/2014

    Recently I heard a report on NPR about the new "1 Baby, 3 Parents" treatment. Despite the titillating title suggestive of another social commentary on Polyamory and progressive marital relationships, this was actually a story concerning the public consultation of treating mitochondrial diseases.

    What are Mitochondria??

    Mitochondria

    Mitochondria are essentially batteries in our cells. They exist to convert metabolites into ATP, generating 90% of energy which power our cells, enabling us to move, think and live everyday. The quirk about mitochondria is that they began in evolution as single celled bacteria which invaded eukaryotic cells 109 years ago to form a symbiotic relationship. This means that they are encoded by a separate set of DNA from nuclear DNA, encoding the bulk of our genetic information. In most people mitochondrial DNA is inherited from the mother. Thus, mitochondrial mutations are carried in the mother's eggs and is a genetic disease.

    What are Mitochondrial Diseases??

    Mitochondrial diseases affect 1 in 250 births and 1 in 10,000 people are sufferers in adulthood. Diseases of mitochondria are caused by mitochondrial DNA mutations which result cell injury and death. Most damage is caused in the brain, heart, liver, skeletal muscles, kidneys, endocrine and respiratory systems, where energy usage is heaviest in the body. The United Mitochondrial Disease Foundation in the US and the Rare Mitochondrial Disease Service in the UK give a good list of diseases which ensue from mitochondrial breakdown. In fact, many neurodegenerative disorders, such as Multiple Sclerosis, which I mentioned previously, may be associated with mitochondrial disease.

    What is the excitement all about??

    A few years ago, a group of scientists in Newcastle University, England, discovered a way to carry out IVF-based nuclear transfer, while preserving host mitochondrial DNA. The technique transfers the nucleus of a fertilized egg (donor zygote) into another egg (recipient zygote) after the host nucleus is removed (enucleation), while preserving the mitochondria from the host. This technology essentially allows the father and mother (the mother being the carrier of the diseased mitochondria genes) to preserve the bulk of their genome in the nucleus, while using another woman's egg containing healthy mitochondria. The new embryo effectively still contains genetic information from the original two parents. Initial experiments have shown that the nuclear transferred-eggs divide normally into blastocytes for up to 8 days, ready for pre-implantation. This could prove to be a vital treatment for people who have a family history of mitochondrial diseases and plan to have children. See diagram:

    They published some interesting reports in Nature here:

    Pronuclear Transfer

    and here:

    Therapy

     

    The fuss in the media!

    This should be a safe technique, which, if trials are successful, can be implemented to rid the world of another dozen intractable diseases. As with all novel innovations, however, people are liable to be concerned with misuse of this technology in designing healthier children, or making "designer babies". A panel in the UK has been set up to review the policies on taking this technology into the clinic. They recruited Doug Turnbull, one of the original scientist on the paper, to advise the panel.

    Understandably, religious and conservative groups are the first to wrangle with this policy. However the media exacerbates the problem by highlighting sensationalist titles of "3-Parent Baby plans". Typical offenders like the Daily Mail and this Christian magazine are exceptionally adept at turning stories of scientific progress into facetious trollop. But occasionally some news outlets (the Guardian) get it right and do a good job of giving a balanced, informative message.

    Charisma