In an EXTREMELY near future (the story is set in June 2028 of the Gregorian calendar), there are some people that use the gene therapy because they want to change their physical appearance.

For example, Farah Raymonde Julien-Silvestri is a 30 years old dyadic cisgender woman of European descent (her paternal grandfather was a Frenchman, her paternal grandmother was a Scotswoman, her maternal grandfather was a North Italian, and her maternal grandmother was a Basque). She naturally has a skin that is the same colour as Zucchero's, round blue eyes, and wavy milk chocolate brown hair, she is 1.75 metre tall, and she weighs 70 kilograms. Farah always dreamed to be as tall as Richard Kiel (2.18 metres tall). She also wants to have a blue whale-like blubber, and an albino fur as dense as a mountain gorilla's and as oily as a seal's. Farah has the wish to be fertile forever: she would like having the gene of queen naked mole-rat's ovulation (contrary to almost all other female mammals, queen naked mole-rats make new ovum/eggs all their lives). She would love to have the same skin colour as Morgan Freeman, and she loves the colour of her eyes, but she always wanted to have epicanthic folds à la Lucy Liu. Farah asks a professional scientist to do genetic surgery on her for having all the physical features she wanted to have.

So, I wonder if, in real life, genetic surgery could radically transform humans as my character wishes.

EDIT: Thank you for the answers. However, Farah also wants baboon-like whiskers, and a voice as deep as a cow's.

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    $\begingroup$ Just as an aside (because the existing answers cover most of the bases), making people taller is a surgical procedure. It is painful, extraordinarily invasive, and will not result in immediate proportionate change. This will not change with gene editing, for the reasons covered by @user253751. $\endgroup$
    – jdunlop
    Commented Mar 20, 2023 at 20:45
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    $\begingroup$ Please do some basic research before asking questions here. $\endgroup$
    – Ian Kemp
    Commented Mar 21, 2023 at 18:15
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    $\begingroup$ If you want it to be possible in your world, just declare it so. I don't understand why people want justification for magic. $\endgroup$
    – Tony Ennis
    Commented Mar 21, 2023 at 19:40
  • $\begingroup$ @TonyEnnis: Firstly -- who said anything about magic? Secondly -- just because you don't understand why a better-justified world is more appealing to many readers, that doesn't mean that their desire isn't legitimate, or that writers should stop trying to fulfill it. $\endgroup$
    – ruakh
    Commented Mar 22, 2023 at 2:09
  • $\begingroup$ @ruakh what the OP describes, and desires in 2028, is so far beyond current tech that it is magic. So if the story needs it, the OP should just add it without trying to explain how it works. Magic. there's nothing wrong with it. $\endgroup$
    – Tony Ennis
    Commented Mar 22, 2023 at 14:46

5 Answers 5



At least not anytime in the near future. And even then... Most of what you want is simply just not possible thru "genetic surgery".

Crispr (Gene editing technology) can replace DNA inside of living cells... But just because your DNA has been changed to make you taller, you won't suddenly become taller.

DNA provides a blueprint for your body. But much as your house's shape doesn't magically change when you change the blueprint... changes to your DNA cannot magically alter your body either.


Once your growth plates die you stop growing, doesn't matter what your DNA says... As a 30 year old Farah's growth plates are dead, there is not a way to make her taller by just changing her DNA. Modern surgery exists to make someone taller... But I don't think they can increase your height by .25 meters.


This one is more possible (Though not in the next 5 years). Your skin replaces itself once a week (or something like this). And hormonal changes can trigger an increase/decrease in hair. So this one is totally possible, with just gene editing (I think).

Blue whale like blubber

Not sure about this one, One the one hand, I think it should be possible, as your DNA determines where your fat is stored.. But at the same time I remember that one of the problems that liposuction has is it can lead people to get a lot more visceral fat (inner organ fat) if it is not accompanied by a lifestyle change. Because they no longer have the fat cells on their gut, so they store fat where they have fat cells. This can lead to major health problems. My takeaway from this is that the distribution of your fat is determined by your genetics from birth (based off of where you have fat cells), but after that... Where you store fat is based on where you have fat cells... SO having Blue Whale blubber gene won't make you have blue whale blubber.. This would require major surgery to do.

Morgan Freemen Skin Color

Possible. Not with today's Crispr... Possibly not with Crispr 5 years from now... But possible.

Epicanthic Eye Folds

Once again, DNA is the blueprint, not the building... You could have the DNA for epicanthic eye folds.. But unless you had that from birth, you won't have it. It is however possible to achieve with modern surgery.

Naked Mole Rat egg production

No idea. As we currently don't know how to give someone Naked Mole Rat resistance to cancer, and there is a lot more interest (research) there then in egg reproduction, I would say the probability of that being tackled in the next 20 years is pretty low...

Also no idea if having the genes is all that is required, or if it would require a structural change.


While it is possible that gene editing could give someone blue whale blubber, 2 meters of height, white fur, and a naked mole rats egg production: That someone would have to be a recently fertilized egg... As major structural changes require either extensive renovations (Major non genetic surgery) or to have been made before construction has gone on for too long.

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    $\begingroup$ Skin is a complex and multi-layered animal. The outermost layers are replaced in a matter of weeks but some layers are never replaced; that's how you can have permanent scars and tattoos. I suspect that increased hair generation and modified pigmentation will require some changes to the deeper layers. $\endgroup$
    – Cadence
    Commented Mar 20, 2023 at 20:13
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    $\begingroup$ One thing to keep in mind for your ruling on height is that gene therapy combined with hypothetical methods of inducing or introducing stem cells in key areas to recreate the growth plates as needed could create the desired result. However, by the strict phrasing of the question you are correct, so it's perhaps not an important thing to mention. $\endgroup$
    – Onyz
    Commented Mar 21, 2023 at 17:29
  • $\begingroup$ @Onyz.... I Hadn't thought about the ability of stem cell therapy to induce growth. The only method I thought of involved breaking bones and medieval rack like torture... $\endgroup$
    – Questor
    Commented Mar 21, 2023 at 17:40
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    $\begingroup$ Baboon whiskers look hair like. We can introduce hair growth now... Though not very well (as the many bald men will tell you). $\endgroup$
    – Questor
    Commented Feb 29 at 23:21
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    $\begingroup$ Deep voice. Structural change in the larynx... I believe the larynx stops changing after puberty. If anyone knows otherwise... please correct me. $\endgroup$
    – Questor
    Commented Feb 29 at 23:24

The fundamental problem here is that genes are only templates used by cells to make things. You can't write "blue walls" on your house plans and then have blue walls; you can't sketch some lines and have an extension spring up; you certainly can't scribble over something and have it disappear. You have to actually repaint or build or demolish these things as well.

Adding chemicals is easy

A lot of cells are constantly working, even to stay the same. Your entire outer layer of skin cells falls off every 2-4 weeks and your skin cells keep making more of themselves - using the template. So if you edit that template, you should see the results in several weeks at the most.

It's also possible that even with cells that don't do much, you just add a marker to the template that says "make this template anyway" and it does get made.

Scientists do this all the time with microbes. If you want bacteria to make some chemical, you inject DNA that says "hey, I'm an important template, build me" marker and then the chemical, and it starts making that chemical. That's how you get fluorescent bacteria and yeast that produce spider silk. And how some of the COVID-19 vaccines were made. You get bacteria with this extra useless (for them) chemical inside of them that they can't use; when you have enough, you dissolve them up and use some kind of purification process to take the chemical you wanted.

I don't think we do it on humans.

So if you want to make skin cells produce blubber, or melanin (carefully tuned to match the concentration in Morgan Freeman's own skin cells), that's entirely plausible. You'd need a marker that says "make this template if you're a skin cell" or else a way to make sure only the skin cells get the template.

Note that DNA only specifies proteins. Melanin is a protein, so it can be made directly. You just tell the cell to make melanin. Quite easy, if you're trained in this stuff. Blubber is fat, so it's substantially harder to tell the cell to make the proteins that assemble other molecules to make fat. I don't know whether we know all those proteins or not. There's a much higher chance of unintended side effects.

Anyway, it's entirely plausible that it will be happening in shady labs, with significant risks, in foreign countries with less regulations, in 2028. It won't be mainstream medicine by that time.

Whatever we do with the blubber, we could also do with the seal oil.

Signalling is hard

She wants to be as fertile as a naked mole rat. (Why? Childbirth is painful. But anyway...)

The hormones in different species are mostly different. This won't happen by taking some "fertility gene" from a naked mole rat and implanting it into a human. No, we have to understand what chemical signals make humans develop eggs and then invent a gene that makes those signals keep happening. Probably, the second half is just inserting a chemical into ovary cells, but the difficult part is understanding what chemical to insert. (A plumber whacks a pipe with a hammer and the problem goes away. He gives an itemized bill: \$1: hammer. \$19: travel time. \$230: knowing which pipe to whack)

Changing body parts is extremely hard

You didn't mention this one, but some people want additional arms instead of legs? That's definitely not happening.

If you want to do this to an embryo, there's some kind of chemical signal that tells each limb whether it's an arm or a leg. We don't know what it is, exactly, but it's there. If we find that signal and override it we can make embryos develop with 4 arms. But if you want to do this to an adult that doesn't work because they already grew the legs. You need to change the legs into arms, that's way way harder than just telling them to be arms in the first place. Probably the easiest way is to cut the legs off entirely, then give the stubs signals that tell them they are still a fetus and they need to grow new arms! Needless to say, that's pretty risky. And we have no idea how to do it yet. We still won't in 2028.

Hair follicles are body parts

Your character wants fur as thick as mountain gorilla. The problem is that she already has a certain number of hair follicles, and wants to grow more, a lot more. Like 1000x more. And a hair follicle is not just a single cell but an arrangement of parts; see Wikipedia.

Good luck with that. It may be possible to program skin cells so some of them turn into hair follicles - but it's absolutely not going to happen to 2028. And you couldn't do it with mechanical means (like cutting out the middle of a leg to make it shorter like an arm) because you'd have to do it zillions of times. Better to just wear a fursuit.

Hair isn't even made of cells, in case you were wondering.

  • $\begingroup$ Re: the egg cells issue, there's also the problem that a mammal is born with all the oocytes they'll ever have. You could maybe add signaling that caused more of them to develop into eggs at a time, but you're not going to be able to make more without pluripotent cells. $\endgroup$
    – jdunlop
    Commented Mar 20, 2023 at 20:39
  • $\begingroup$ @jdunlop I'm thinking you can figure out ways to make cells become pluripotent, or whatever they need to be, as that is probably just another chemical signal controlled by genes. However it will be harder than replicating an already known signal. $\endgroup$ Commented Mar 20, 2023 at 20:40
  • $\begingroup$ I mean, we can make adult cells become adult stem cells, but I don't know of any process in nature that can make them become embryonic stem cells, which is what you need if you want to make brand new eggs. So maybe we could figure something out, but it wouldn't be a signal found in nature, it'd be direct chemical intervention. $\endgroup$
    – jdunlop
    Commented Mar 20, 2023 at 20:42
  • $\begingroup$ @jdunlop Of course. They have genes controlling all these switches; if you allow editing the genes, anything can be possible. But probably not by 2028. Consider: How does an embryonic stem cell know that it's an embryonic stem cell? $\endgroup$ Commented Mar 20, 2023 at 20:44
  • $\begingroup$ Inasmuch as a cell can "know" anything, because it has the mechanisms to become any other cell. Those mechanisms are discarded when pluripotent cells become tissue stem cells, and the process is irreversible (because the necessary mechanisms are discarded, rather than unexpressed). Undifferentiated adult stem cells can only differentiate into specific tissues, which is why the embryonic ones are so interesting from a therapeutic perspective. We could probably make embryonic ones from scratch, eventually, but making the body make them seems less than plausible. $\endgroup$
    – jdunlop
    Commented Mar 20, 2023 at 20:49

Semi-hard no on this. You have to differentiate between genotype and phenotype. Genotype is what's in your nuclei, and phenotype is what that code builds.

Gene therapy can change what's in the nuclei, but that only changes which proteins the nuclei create. The best you can expect to get from gene therapy is for your cells to start generating the proteins that it should have been generating all along to get a specific chemical effect.

Going from chemistry to structure is hard. You can't just pull out the parts of a cell you don't like as if you were refinishing your bathroom. It would be more like trying to change out the valves on your car while it was still running.

If you start throwing a different kind of protein at a cell, it doesn't just adapt to figure out how to use it. Most of the time, you kill it. If you change too much at once, you create an immune system conflict and it kills you.

The imagined use of gene therapy is that you inject someone with RNA that goes in and re-writes your DNA, but it doesn't really work that way. Most of your DNA is inaccessible because it's folded up tightly in your nuclei. This means that, to properly re-write the DNA, you'd have to catch a cell when it's in the process of dividing and re-write both copies of it before it packs itself back into the nuclei.

This means, to replace your skin, you would basically have to kill off half of your skin cells, and tell the other half to divide so that you can re-write them. This would be like having cancer and AIDS at the same time. You'd have to spread it out over a long period (the bigger the organ, the longer the period), and probably have to filter the junk out of your blood so that your liver and kidneys don't collapse. You'd probably also have to reset your immune system by regrowing all of your bone marrow.

Overall, I won't say that it's impossible, but it's going to be centuries before we can do anything close, and it'll be more centuries before it's something with the relatively low health impact of cosmetic surgery.


As others have said, this is essentially impossible with gene therapy technology. Ignoring the problems of knowing whether a gene will work as intended(or at all) in a human, the genes have already been expressed, so the traits will never manifest even if the edits are made.


There is a way to circumvent this: prompting new cell division and allowing for the expression of new genes. @user253751 briefly touched on this in their answer:

Probably the easiest way is to cut the legs off entirely, then give the stubs signals that tell them they are still a fetus and they need to grow new arms!

By growing the tissues separately, or on the desired graft site, you could achieve the desired phenotypic alterations. As mentioned in chat, though, this is no longer in vivo alterations, and thus is not really "gene therapy."

  • $\begingroup$ I just realized this likely constitutes a frame challenge and thus should be restructured as such, but am unsure how exactly. $\endgroup$ Commented Mar 22, 2023 at 2:01


We have no idea how to change height or skin colour by altering the genetics of a living animal.

We know some stuff about modifying embryos. But I suspect we are not even much good at modifying rat embryos on an individual basis.

Giving someone an extra foot of height, a dense coat of fur, different skin colour, or enhanced fertility is right out.

Do not set your story in 2028. Set the story in 2828.


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