tag:blogger.com,1999:blog-1513704378254120283.post5649323469885228180..comments2024-01-23T13:58:48.688-08:00Comments on The Trenches of Discovery: The human machine: replacing damaged componentsShaun Hotchkisshttp://www.blogger.com/profile/04832423210563130467noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-1513704378254120283.post-87287249311293332492014-05-07T03:38:25.771-07:002014-05-07T03:38:25.771-07:00You're quite right that a lot of disorders hav...You're quite right that a lot of disorders have a genetic component, but the key difference is that most of these don't tend to kill the sufferer until later in life and so they still have time to reproduce. Cancer, for example, is generally a disease of middle/old age so people tend to have already had kids by this point. Also, as you indicate, many of these disorders are the product of which combination of genes you have, and no single gene is solely responsible for the condition. The prevalence of these kinds of genes is pretty high in the population at large, but most people don't have the specific combination required to cause disease. The mutations responsible for monogenic (i.e. single-gene) disorders are far more rare, and they're the ones that might begin to expand in response to gene therapy.<br /><br />I think that this can be managed properly with a strong post-treatment focus for patients receiving gene therapy. A patient who receives treatment for a monogenic disease could have their gamete (i.e. sperm or ova) screened prior to in vitro fertilisation, so that they can be confident their offspring won't inherit the disorder. There is already a screening programme in place to let carriers of recessive genetic diseases know what the risks are of their children being sufferers, and some do choose to go with IVF to reduce the risks. At the minute, though, this is prohibitively expensive and not feasible to cover the entire populous, but one day it might be. <br /><br />In some cases, though, this isn't possible. For example, in X-linked recessive disorders (such as haemophilia) an affected mother has no chance of having a son who does not suffer from the disease, since she has 2 copies of the mutated gene and the son can't receive a healthy copy from his father (since boys only inherit the X chromosome from their mother). Similarly, a father with an X-linked dominant disease (such as Rett Syndrome) can't have a daughter without the disease, as she will definitely inherit the mutated X chromosome from him. In these cases screening would limit them to having children of only one gender, which may be preferable to having a child with the disease but that is personal choice that each patient would have to make.James Felcehttps://www.blogger.com/profile/14031758835739415241noreply@blogger.comtag:blogger.com,1999:blog-1513704378254120283.post-50994957264779860072014-05-06T11:12:47.551-07:002014-05-06T11:12:47.551-07:00Aren't many disorders somewhat genetic anyway....Aren't many disorders somewhat genetic anyway. Therefore, this new type of treatment doesn't necessarily raise ethical questions that many other medications don't already. For example chemotherapy might allow someone who has cancer to reproduce and pass on genes that are more prone to cancer and therefore we are producing a society heavily prone to cancer. Or is the point that, although those questions were more or less always in the background, treating a disorder that is 100% inherited, rather than a disorder where the inherited thing is just a proneness, brings the question up much more blatantly?<br /><br />It's definitely a frightening question though because there really don't seem to be any obvious ethical ways out. It becomes a clash between what is good for the society and what is good for the individual. Eugenics is also such a clash, but there it is what is "good" for the society vs what is bad for the individual. And here it is what is good for the individual vs what is bad for the society. Eugenics can be clearly argued to be wrong because not doing it doesn't actively damage society, we would arguably still improve and reach the same point in the long run. But with this, there is the genuine risk (as you point out) that treatments such as this, taken to the extreme could make a human species that is incredibly fragile and dependent on medication to survive. Shaun Hotchkisshttps://www.blogger.com/profile/04832423210563130467noreply@blogger.com