• Question: Do you think we can use DNA and genetic engineering to completely to abolish genetic diseases?

    Asked by dmahm to David, Thiloka, Shonna, Shobhana, Ryan, Ross, Rebecca, Rachel, Patrick, Nina, MattyB, Matthew, Marianne, Lorena, Kate, Kaitlin, James, Ettie, Emmanuelle, Deepak, Anabel, Ambre, Alex, AlexAgrotis, Aina on 12 Jun 2019.
    • Photo: David Wilson

      David Wilson answered on 12 Jun 2019: last edited 12 Jun 2019 12:53 pm


      There has been real progress recently in Gene Therapy to do this for some diseases (Spinal Muscular Atrophy in humans)

      Gene therapy is an experimental technique that uses genes to treat or prevent disease. This technique allows us to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery. There are several ways to do this. We can replacing a mutated gene that causes disease with a healthy copy of the gene. We can inactivate a mutated gene that is functioning improperly. Or we can introduce a new gene into the body to help fight a disease.

      Although gene therapy is a promising treatment option for a number of diseases, the technique remains risky and is still under study to make sure that it will be safe and effective. Gene therapy is currently being tested only for diseases that have no other cures.

    • Photo: Ryan Beveridge

      Ryan Beveridge answered on 12 Jun 2019:


      Gene therapy as described by David is an incredible tool when you have what are called ‘single gene disorders’, these are diseases caused by a problem in one gene.
      A study two years ago helped a young boy who had a genetic disease that stopped his skin from sticking to the underlying flesh, it was caused by a mutation in an anchor protein that normally anchors the skin to the flesh. A team of Italian and German scientists managed to take some of the boys skin, insert a working copy of the anchor gene, grow the skin and then transplant it to the boy. So far it looks like this has cured the boy, really incredible and inspirational work!

      In order to abolish other diseases completely you would have to edit the DNA of someone before they are born, this has the potential to be very dangerous. We have ways of doing this but we do not yet know how accurate they are. If they are making dangerous changes that we do not see until a person is born then we could be causing unnecessary suffering.

      Once the process if understood more thoroughly the potential is limitless, however there is also the danger that only rich people are able to access this sort of technology. We have to make sure that this kind of technology isn’t used frivolously and that everyone who needs it has access to it.

    • Photo: Marianne King

      Marianne King answered on 13 Jun 2019:


      I believe that gene therapy will be invaluable in treating diseases that are caused by mutations in just one gene. The disease I work on is Rett Syndrome, which is caused by mutations in one gene, MeCP2, that helps our brain development. It’s been seen in mice that have the same mutation, that replacing the mutant gene with a healthy gene almost completely abolishes their symptoms. Symptoms in Rett Syndrome start to appear around 18 months old, so it’d be possible to act very early in life too.

    • Photo: Rebecca Moon

      Rebecca Moon answered on 13 Jun 2019:


      No I don’t think it will completely abolish genetic diseases, but it may make them more treatable when they do occur. Often someone will be diagnosed with a genetic disease but they are the first person in their family to have the condition. This could be because of a de novo mutation (the mutation was not present in their parent but arose as a fault during meiosis) or because in the case of an autosomal recessive condition (for example cystic fibrosis), previous generations have been carrying a single copy of the mutated gene, and it is only because two people carrying the gene have had a child and the child inherits two copies that they have the condition. So even if genetic engineering enabled embryos without that gene fault to be generated, in that family, they would not have felt the need to undertake that approach. As such, it is likely that genetic continue to exist, but treatments to activate or inactivate genes in patients carrying faulty genes might become more common ways of treating genetic disorders.

    • Photo: Kaitlin Wade

      Kaitlin Wade answered on 14 Jun 2019:


      I think that’s a great question. There are lots of scientists working on gene therapy and engineering at the moment and I think it has great potential for eradicating some diseases, especially those that are mainly determined by genetic variations. For more complex diseases, however, like cardiovascular disease, Alzheimer’s disease, cancer and obesity, I think we have way more research to do in order to firstly understand what genetics has to play and whether we can tap into that information to at least get rid of some of those diseases in the population.

    • Photo: Nina Rzechorzek

      Nina Rzechorzek answered on 15 Jun 2019:


      Thanks for asking such an important question! I think the other scientists have given really great answers to this, and certainly I agree that gene therapy holds real promise for certain genetic disorders in which there is a ‘simple’ or single genetic aberration that might be corrected. Examples include an inherited cause of progressive blindness called choroideremia and some mitochondrial disorders; you can read more about these stories here:
      https://wellcome.ac.uk/news/promising-first-results-gene-therapy-trial-inherited-blindness
      https://wellcome.ac.uk/news/gene-therapy-restores-sight-people-inherited-blindness
      https://mrc.ukri.org/news/browse/mitochondrial-diseases-could-be-treated-with-gene-therapy/

      However, for many diseases that are influenced by genetics, things are far more complicated, and gene therapy is unlikely to provide a cure or abolish the disorder for future generations. These more complex disorders like some immune-mediated diseases (e.g. asthma, multiple sclerosis), several cancers, obesity, dementia, and heart disease often involve the contribution of many genetic variables together with lifestyle factors and environmental influences. People may carry genetic variations that have the potential to contribute to disease, but only if they are exposed to certain other risk factors – in such cases these people could pass the genetic variation ‘silently’ onto their offspring who may later develop the disease when they are exposed to those risk factors. For the same reasons though, exploring the genetic contributions to these diseases may still hold potential in terms of disease modification or prevention – for example if we knew ahead of time that one of our genetic variants puts us at high risk of a certain disease, we could potentially modify our lifestyle to reduce this risk.

      I think the greatest promise of genetic engineering is in being able to replicate (in laboratory model systems) each of the genetic variants that we think might be important to a disease process – one at a time, in isolation, and then in various combinations together to figure out just how important the contribution of each of these is. Being able to do this on an otherwise identical genetic background is key to controlling for complex genetic influences on all the molecular pathways affected in a disease process. The emergence of iPS technology means that we can grow a cell line from a patient carrying a genetic mutation, and genetically engineer it to produce an ‘isogenic’ gene corrected control line to compare with in each experiment. Again, however, this would be much more complicated for the diseases involving many genes, and since (for humans) we can only do this using cells lines, what we see in a dish may not be relevant to the whole organism.

      To add yet another layer of complexity, ‘epigenetics’ can play an important role in disease development and expression. Just like the same musical score can result in many different versions of a concert, the same basic genetic code might not lead to the same expression of disease at the level of the organism – here are some good online resources that tell you more about epigenetics:

      A short introduction to epigenetics


      https://wellcome.ac.uk/news/scientists-discover-how-epigenetic-information-could-be-inherited
      https://www2.mrc-lmb.cam.ac.uk/groups/jes/epigeninst.html

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