Genetic engineering and disease

[Ziggy Stardust]

I don't know a whole lot about genetic engineering, but in one of my classes today we were having a discussion on the subject. I got into an argument with one of my classmates. I argued that genetic engineering could be problematic in the theoretical case of being able to completely manipulate the genome of an infant before it is born. That is, Gattaca-level control of genetics. I argued that this could be a problem because it would reduce variance in the human genome. Most people have similar ideas of what "perfect" is, with relation to children. As in Gattaca, pretty much every child born would be attractive, athletic, etc. There won't be any ugly people, deformed people, or what have you. I argued that this could be a problem in more than just an ethical sense, in that by reducing variation in the human genetic code (as would happen after several generations of such genetic engineering), you make the human race weaker in the long run. For example, a disease could wipe out a large portion of the human race.

My classmate argued that if you have the level of genetic engineering to do what I described, you could make all children virtually immune to any disease. As I know very little about genetics (that is, no more than what a few biology classes have told me), I did not have much to rebut this with. My question is: does having literally complete control over the genome mount to being able to supercede any of the practical issues that could arise? Could you code children that would be virtually immune to disease, or is it still possible for a disease we don't know about, or a mutation of an existing disease, to seriously fuck things up?

[Knife]

As I understand it, no. Molecules do what they do because of their shape, so if you change the shape of a particular macromolecule to prevent, say a virus, from being able to attach to it, you change how that particular molecule interacts with what ever it interacts with naturally. Depending on what exactly we're talking about, it could be meaningless or a disaster.

With bacteria, you come into the problem where microbes can pick up various new abilities themselves. If you change something in a newborn to prevent a bacterial disease, nothing says that bacterium can't eventually pick up the genes for a protein that counters it. Think Penecillinase.

I'll let someone who knows more than I see if such blatant manipulation would cause a problem with autoimmune disease.

[Nephtys]

Symmetry and genetic similarity does weaken a species from specific threats. Nature's way of survival is to spread out traits of all kinds from random mutation of course, and the ones that are beneficial are passed on. It's impossible to determine what may be beneficial after all.

There's the well documented example that everyone knows of course: The increased distribution of African Sickle Cell Anemia protecting them from Malaria.

So in this case, a specific disease could be very deadly if many people exhibit similar genes. As may things such as recessive, extremely undesirable genetic traits becoming common over generations of effective inbreeding due to a lack of genetic variation in a population.

'Virtually Immune' to disease is as far as I can see, a pipe dream. Some genetic conditions are obviously cured, but how are you going to gene engineer someone to be able to avoid the thousands of malevolent bugs out there? It's not something you can write off with merely building 'a stronger immune system'.

[Admiral Valdemar]

If you have the technology to produce designer babies, then the idea of genetic bottlenecks is well know and easily remedied. You simply make it a point of law to govern how much of the population tinkers their genes a certain way or add in randomised gene sequences rather than go exactly with what is wanted.

You couldn't anticipate every factor that would affect the phenotype this way, unless you had some mighty computing power. But it should be simple enough, given the Human Genome Project's data, to know where possible negative aspects can manifest. Then it's a simple case of retroactive gene therapy if the condition appears after the fact.

In the end, we still don't have a real clear picture about a great many biochemical pathways or what genes activate them or what have you. We have general guidelines, though it's been a trial and error approach thus far. If a government allows such personal genome modification, then it would only happen after we've elucidated a greater percentage of our biochemistry. To say it is as easy as gene A turns off trait B and we have a superman, is quite simplistic. Gene A might well grow you two hearts and neglect forming your eyeballs, but at least you stop a specific cancer from happening.

Incidentally, I was going over the protocol of a study on recombinant S. cerevisiae (that's baker's yeast) using human oestrogen and androgen genes. We can learn a great deal from experiments in transgenic organisms that will shape how we play around with genetics in the future, though naturally a cell culture of yeast isn't going to give you a whole picture like a full human organism working fully.

[Junghalli]

I believe that many of the physical traits that we consider attractive are signs of health and fitness, so generally a better-looking population will probably be a healthier one. At the same time, yes, it probably would lead to reduced genetic diversity. Although whether that would be a serious problem for the species is another question. The human population is huge enough and diverse enough that we could probably eat the drop in genetic diversity and still be fine; "good-looking healthy people" can still encompasses a pretty physically diverse population. The kind of disease-resistance problems you get with severely inbred populations shouldn't be much of a factor, because we're not talking anything close to a genetic monoculture here. Although if there are certain specific mods that almost everyone gets it could be a concern.

And, as Admiral Valdemar points out, with a little long-term planning a civilization that employed genetic engineering on such a massive scale could easily take steps to prevent such a thing from happening. One could, for instance, simply store away records of "extinct" genetic patterns in the odd chance that some of them may be useful. Or just offer subsidies to some people to not have their children engineered in order to preserve "wild" genotypes.

Engineering-in virtual immunity to disease doesn't sound too feasible to me, although you could probably increase the population's resistance to infectious disease significantly. You might have better luck with nanotech autoimmune "prosthesis".

[Broomstick]

The downside to programming in stronger immune responses is that there are some diseases that kill by immune OVER-response.

Total control over the genome may actually INcrease diversity, depending on what humanity decides to do with it... but the unanticipated has a way of biting one on the butt. We can't engineer for the unforeseen.

[Starglider]

The downside to programming in stronger immune responses is that there are some diseases that kill by immune OVER-response.

The fix for that is making the human immune system more intelligent. There is tremendous scope for this, even restricting the design to biochemical / DNA computing.

[Admiral Valdemar]

I concur with Starglider; even if we can't become cyborgs or nanotech doesn't pan out as hoped, the human immune system is more than capable of countering any foreign intruder. The issue is tweaking it to adapt to the likes of AIDS producing pathogens which can't be adapted to via the ad hoc methods of natural selection.

If we can simply tailor our genome to anticipate such threats, then the game is won. Then all that stands in our way are unforeseen genetic diseases (readily dealt with given the capabilities discussed) and physical problems down to inefficient biomechanics e.g. The female hip, the knee, reverse wired retinas and so on. Homo sapiens Mk. II would be a far better endeavour.

Did I mention catgirls? =^_^=

[Shroom Man 777]

Don't they say that it's better to inter-breed with other ethnicities/races and whatnot because a a very diverse multiracial genetic heritage is actually more healthy than those who breed only with their own kind and don't assimilate traits from other populations?

I know that's oversimplifying but...yeah. I heard it. From someone.

Genetic engineering could be done to create a "heterogeneous cocktail" of genes.

Like a Halo-halo

[Lord of the Abyss]

Total control over the genome may actually INcrease diversity, depending on what humanity decides to do with it...

One thing that occurs to me, is that a hidden assumption behind arguments that genetic engineering reduce diversity is that it will be controlled and directed by a single group. It seems more likely to me that every nation that has the technology and the desire will create it's own program, and it's own set of alterations.

Another hidden assumption in the argument that making us all healthy and attractive and so forth will make us more identical, is that we won't modify our insides more than our outsides. "Attractive" might push us genetically together, but "healthy" and "athletic" could involve major internal alterations. And in a world with more than one group doing the alterations, those changes could be quite different from one group to another. In fact, far from destroying diversity, the result could be the creation of multiple human species, at least in the biological if not social sense; the results of different groups tinkering might not be able to interbreed.

As for making people immune to disease, perhaps one effective approach is to do what evolution is bad at and make massive leaps in design instead of the incremental ones that evolution uses. For example, if one had enough biological knowledge to design an immune system from the ground up, and the genetic engineering knowledge to build it into people, I'd think the great majority of infectious diseases would be stymied for a long time. The bigger the change, the harder a time infectious agents have adapting; you don't see many plant infections attacking humans.

[Knife]

I concur with Starglider; even if we can't become cyborgs or nanotech doesn't pan out as hoped, the human immune system is more than capable of countering any foreign intruder. The issue is tweaking it to adapt to the likes of AIDS producing pathogens which can't be adapted to via the ad hoc methods of natural selection.

If we can simply tailor our genome to anticipate such threats, then the game is won. Then all that stands in our way are unforeseen genetic diseases (readily dealt with given the capabilities discussed) and physical problems down to inefficient biomechanics e.g. The female hip, the knee, reverse wired retinas and so on. Homo sapiens Mk. II would be a far better endeavour.

Did I mention catgirls? =^_^=

Won't that bite us in the ass with things like autoimmune syndromes? Won't and more effective CMI or HI make things like common allergies all the way up to Lupis a lot worse?

[Surlethe]

Won't that bite us in the ass with things like autoimmune syndromes? Won't and more effective CMI or HI make things like common allergies all the way up to Lupis a lot worse?

I think that's what Starglider means by making it smarter as well as more powerful. If it's smarter, it can more easily distinguish between invaders and friendly cells.

[Knife]

Won't that bite us in the ass with things like autoimmune syndromes? Won't and more effective CMI or HI make things like common allergies all the way up to Lupis a lot worse?

I think that's what Starglider means by making it smarter as well as more powerful. If it's smarter, it can more easily distinguish between invaders and friendly cells.

Yeah, but how the hell do you do that? Like RA for example they have no idea why the body decides to attack the joints or Lupis for another example....

[Admiral Valdemar]

Assuming the technology involved is that effective, they likely already know what Lupus and similar auto-immune maladies do in detail and how they go about doing it.