Gene Therapy: Can we replace a full genome?

[Waverunner]

It is possible to replace several faulty genes through gene therapy. The question I have is, can we replace all faulty genes by replacing our whole genome? There are several problems of course, e.g. we currently don't know if something is really faulty. For some genes we do know, that they cause several problems but for many others we don't.

Let's suppose that this information is available. We have a perfectly healthy human with a perfect genome. The genome has been optimized with a quantum computer that took into account nearly all possibilities and knows exactly what drawbacks could arise from certain manipulations (e.g. a person with allergies might be less prone to certain types of cancer, is this trade-off worth taking?). If this sounds unrealistic to you, please think of a very healthy normal person, who is supposed to live long.

Would it be possible to replace the whole genome of an ill person, with the whole genome of a healthy person? In other words, is it possible to not only replace a few genes but several thousand genes at the same time?

 

[Waverunner]

In my layman perspective it is much more costly and much more difficult to:

a) Check the genome of a person for faulty genes
b) Look at all the locations of these genes
c) Develop gene therapy for each faulty gene
d) Apply gene therapy, try to replace all faulty genes
e) Leave all healthy genes alone

than to:

a) Replace a bad genome with a "standard" genome that has low suscetibility for disease

 

[Little Bluestem]

If I replaced my genome with a standard genome, would I not become a clone of the person who provided the standard genome?

 

[Waverunner]

If I replaced my genome with a standard genome, would I not become a clone of the person who provided the standard genome?

Yes, I think so. One would have to leave out the genes, that determine a person's look, in order to not look as the clone. Your thoughts and experiences would still be the same since it was your unique environment, that provided them.

In the end, you're probably right. It's not a good idea to replace a whole genome, since it could change a lot of what the person is. It's a scary thought but I guess you could clone perfect soldiers this way.

 

[alex3619]

Hmm, this is a tricky issue. You body would be a clone, but your brain would be you. Brains develop by experience and interaction with the environment in ways that have nothing to do with experience. Also, what about mitochondrial genomes? Also, optimized or not, if everyone did it human genetic diversity would be zilch and any bug or event that genome is susceptible to might wipe out overyone .... you would really need, at the least, a large range of different optimized genomes, optimized differently.

 

[lansbergen]

Would it be possible to replace the whole genome of an ill person, with the whole genome of a healthy person? In other words, is it possible to not only replace a few genes but several thousand genes at the same time?

As for as I know the whole gnome can only be replaced in a eggcell and than stimulate the eggcell to multiply. It would be a clone of the gnome donor. .

 

[alex3619]

It is hypothetically possible to replace every gene in a body, the entire genome. Its just a biomechanical problem, its not impossible. Its also not feasible in the forseeable future, nor is it likely to be cost effective. This comes under the heading of science fiction. There are other ways to achieve similar ends. For example, implanting assistance tissues or organs to complement the things that are not working, such as an engineered pancreas to go alongside our existing one. Cloned and genetically repaired clones of organs are quite likely to be available within decades, though whether they will be cost effective is unknown. Researchers have even had very limited success forcing regrowth of lost body parts.

Transplantation of genes into people currently requires a vector. Plant cell gene imprinting is easier, they blast the cells with gene gun. There is not whole animal to kill. Then they vegetatively grow the plant to find out if the genes took. This can be helped using a marker gene, such as one that makes the roots turn blue.

Using a vector is highly problematic. My guess is that all existing gene therapy has major problems, though I have not kept up to date and could be wrong.

The question as posed though is about future technology. I think this would be better in the community lounge, not other health news and research, because it is highly speculative. Having said that I do think this could be possible within a century or two. To get there though we need highly developed nanotechnology, especially nanorobotics. It wouldn't be easy but there are many good reasons to do something like this.

Bye, Alex

 

[Waverunner]

It is hypothetically possible to replace every gene in a body, the entire genome. Its just a biomechanical problem, its not impossible. Its also not feasible in the forseeable future, nor is it likely to be cost effective. This comes under the heading of science fiction. There are other ways to achieve similar ends. For example, implanting assistance tissues or organs to complement the things that are not working, such as an engineered pancreas to go alongside our existing one. Cloned and genetically repaired clones of organs are quite likely to be available within decades, though whether they will be cost effective is unknown. Researchers have even had very limited success forcing regrowth of lost body parts.
Bye, Alex

In my eyes, cost effectiveness will not be a problem. I saw several talks by Athony Atala, who currently works at the Wake Forrest Institute for Regenerative Medicine. They printed a kidney (no clinical use) within 7 hours on a TED stage. And this is just a prototype, things will be much faster in the future. 10 years ago they already printed a bladder and implanted it to an ill patient, who is at perfect health now. Another problem is FDA approval, the average drug takes about 15.5 years till approval in the US, who knows how long it will take for printing organs.

http://www.slate.com/blogs/future_t...working_to_regenerating_and_3_d_printing.html

 

[alex3619]

Hi Waverunnner, I consider grown organs to be almost viable, though complex organs are still causing problems. When I mentioned cost effectiveness, I was referring to whole genome replacement. Cloned organs and artificially grown organs are a very real option in the future, and I expect over time they may cost a lot less than current organ transplants. This is because there will be minimal rejection, if any at all, so no need for immune suppressants and the organ may survive much longer than a donated organ.

Such short printing of a kidney probably hides weeks of preparation. I don't think its likely to be that quick due to the complexities. The actually growing is not the problem, its the growing and culturing of enough suitable cells to form the organ.There is also the question as to whether or not it was functional. A bladder is a relatively simple organ. A kidney isn't.

In rare cases though it might be found that the scaffolds used do induce an immune response. In such cases then immune suppressing drugs might be needed until the scaffold is absorbed (presuming they use a degrading scaffold).

Bye, Alex

 

[Waverunner]

Hi Waverunnner, I was referring to whole genome replacement.
Bye, Alex

Sorry, Alex, that was my mistake. Regarding the organ printing, I have no insight of course but the printing itself seemed easy. The way of getting there was unbelievable hard. During his TED talk, Prof Atala was printing a kidney on the back of the stage but because it takes 7 hours and he only has 15 minutes, they already had printed a kidney in the morning. If it was that expensive and needed a preparation time of several weeks, they wouldn't have done it in my eyes.

 

[Waverunner]

In my layman perspective it is much more costly and much more difficult to:

a) Check the genome of a person for faulty genes
b) Look at all the locations of these genes
c) Develop gene therapy for each faulty gene
d) Apply gene therapy, try to replace all faulty genes
e) Leave all healthy genes alone

than to:

a) Replace a bad genome with a "standard" genome that has low suscetibility for disease

After reading a little bit about the latest developments in full genome sequencing, I have to revise what I said earlier.

a) Easy to do and is included in every fully sequenced genome. However, still expensive (around 3,000 dollars).
b) Included in a)
c) As soon as you have a reference genome, this is not that hard because the process is always the same. Cut out faulty gene and insert healthy gene.
d) and e) Zinc-Finger Nucleases seem to offer a great way of replacing genetic material. Leaving healthy genes alone, shouldn't be a big problem.