By Maciamo Hay,
on 24 April 2014 (updated on 23 May 2014)

Improve your health, looks and intelligence thanks to gene therapy

Advances in genetics now permit to edit one's genome relatively easily. Gene therapy is now used exclusively to fix diseases, but could soon be used by transhumanists for genetic enhancement, such as augmenting one's mental faculties or improving one's physical appearance. What exactly can we modify and what are the risks involved ?

Gene editing tools: copy, paste, delete, fix whatever you want

The 21st century initiated a new era for human genetics, the era of gene therapy. Although gene therapy was first experimented in the 1990's, only single base pairs could be edited, and not always reliably. Many techniques have evolved over the years to modify snippets of one's genome more easily and with accrued accuracy. The most promising, known as CRISPR-Cas9, allows to alter larger stretches of DNA in one time. Using a single short strand of RNA in conjunction with a protein that find and cut a desired DNA sequence (an enzyme called Cas9), the CRISPR method makes it easy to replace, delete, or add any desired sequence of DNA.

Older methods of gene therapy have already been used successfully to treat conditions such as leukemia, multiple myeloma, haemophilia, thalassemia, sickle cell anemia, or Parkinson's disease, and even to confer protection against HIV.

Not only is gene therapy the only cure for genetic disorders like color blindness, cystic fibrosis, sickle-cell disease, Tay-Sachs disease or Huntington's disease, it also has the great advantage of being non-invasive, relatively safe and, in most cases, free of side-effects. The method is so promising that it could be used to cure virtually any kind of diseases caused by genetic factors. The advent of new gene editing tools like CRISPR now even enables the alteration of multiple genes in a single injection.

From designer babies to transhumanism

The 1997 movie Gattaca dreamed up a future society where potential children are conceived through genetic manipulation to ensure they possess the best hereditary traits of their parents. This isn't genetic engineering though. Babies are conceived with the aid of genetic screening prior to an artificial insemination, meaning that the best egg and sperm from each parent are selected to produce the most desirable offspring.

Since the movie was released the cost of DNA sequencing has dropped one million times, passing from one base pair per dollar in 1997 to 1 million base pairs per dollar in 2013. This makes prenatal genetic screening extremely affordable today, and it is indeed already being practiced in a number of countries. Yet it would take many generations to produce superhumans with this method. It may not even be possible for everyone, since genetic selection can only foster pre-existing genetic variants, but not modify the genes. To take an easy example, a couple with blue eyes (a recessive trait that must be inherited from both parents) will only produce blue-eyed children, no matter how many eggs and sperms are analysed for the selection.

Genetic engineering would be the solution to create true designer babies. People could choose to change their baby's DNA to get rid of unwanted potential diseases. As we are at it, why not also remove some "fat genes" by speeding up the metabolism ? Or change the baby's eye colour ? Wouldn't it be nice to increase his/her intelligence a bit as well ? Then we get an "on measure" designer baby.

Genetic engineering raises ethical concerns, as genetic modifications could potentially cause unexpected results. What if the child ends up with a previously unknown genetic disorder, which causes him suffering and shortens his lifespan ? Just the possibility that this could happen may seem like a deal breaker. Not so fast. The whole point of gene therapy is that it can correct genes, and that is also true for those of designer babies. Nothing is irreversible, and that is what makes gene therapy so great.

A lot of people might also object to designer babies on the grounds that the new generation would be "better" than they could ever be. They would envy or fear this new generation of "perfect" individuals. Surely we would lose our jobs to them. Once intelligence has been raised considerably, parents would look stupid, if not pathetic, in their kids' eyes. Then what if we mistook and ended up regretting our designer babies because they looked so different from us anyway ? Once they are born, there is no going back. That isn't true and this is where gene therapy steps in.

The great advantage of gene therapy is that it can correct deleterious genetic mutations or turn genes on and off almost on demand in any individual. In fact, there isn't even a need for designer babies when our children will be able to decide for themselves to modify their DNA later in life. Or seen from a different angle, there is far less to fear from choosing to have a genetically modified/enhanced baby when we know that any potential problem can be fixed later.

Furtermore, the parents themselves could use the opportunity to refine their own DNA. There is no more excuse of fearing that the new generations will be better than us. Gene therapy is so revolutionary that it could be used to change one's physical appearance or improve physical capabilities and mental faculties. It would be possible to change skin, hair or eye colour with a single injection, and even change back later, or choose other tones, almost at will. Unlike plastic surgeries, there is no reason to be afraid to not like the result. Don't like it ? Just edit your DNA and get a new injection. Contrarily to plastic surgery it is pain free and you can't die on the operation table.

The moral message in Gattaca was that genetic selection (or engineering) would ultimately lead to a society divided between the rich, who can afford designer babies, and would become superhumans, and the poor who couldn't afford it, and would consequently end up being ruled by the former. But that argument has already been made obsolete by cheap DNA tests. In the 1990's the US government had allocated $10 billion to test the first complete human genome. 2014 will see the price of a full genome fall to $1,000, and that should fall to a paltry $100 in a few years' time. Gene therapy is also getting increasingly affordable, and by the time it becomes acceptable and legal to use it for personal enhancements (which may still take another decade), virtually anybody could afford it too. It will just be a matter of personal choice, like exercising, choosing a healthy diet or reading to increase one's knowledge.

Toward a genetically enhanced society ?

Few people would question the use of gene therapy to get rid of crippling or deadly diseases. The benefits are so overwhelming that only the most stubborn religious fundamentalist could oppose it. Since the concept of cheap and easy gene therapy to enhance one's looks or capabilities is so novel, most people have never properly thought about the issue before.

There are many arguments in favour of gene therapy for the purpose of improving one's physical appearance. For example:

1. It is safer and far more effective than plastic surgery, which a lot of people are already doing anyway. In countries like South Korea, Brazil, Italy or Greece over a fifth of all women have had plastic surgery, and the USA is not far behind.
2. Less people will be depressed or commit suicide because they don't like themselves.
3. A society made of beautiful people will be more cheerful and pleasant for everyone, and people will not be judged solely on looks anymore, but more for their personality, interests, good actions, etc.

One common objection to using genetic engineering to increase one's looks and intelligence is that people will end all looking the same and thinking alike. Nothing could be further from the truth.

Notwithstanding the ease of editing one's DNA with the new methods of gene therapy, it is doubtful that the genetic engineering part will make it possible any time soon to decide what our face should look like. Altering pigmentation is easy enough. Modifying a few base pairs in your genome will give you fairer or darker hair or skin. But facial morphology is quite another matter. We couldn't even accurately describe a face with words, so how are we supposed to find the DNA sequences responsible for, say, nose shape or the position of cheek bones ? Theoretically it's possible, but humanity will be free of genetic diseases and disorders long before we can master facial design through genetic engineering.

Our genes are like a recipe for making a body. They give simple instructions like how many cells should become a liver and how fast the body should grow. Editing the genome before birth, or at least in early childhood, could modify the way a person grows up. But adults will probably not be able to change their bone structure with gene therapy. Once the bones have grown, you can't shrink them or change their shape. Even though it is possible to rejuvenate the body's chemistry by reactiving genes that get turned off with ageing, it isn't possible to reverse the growth process and to reduce the size of an adult to that of a child or a baby.

The same also applies for the brain structure. It is possible to regrow neurons (both through gene therapy and stem cell therapy) and to modify the brain's chemistry (with medications or gene therapy), but not the connections inside the brain. This is why it won't be possible to radically alter intelligence or personality in adults. At best we could hope to improve the memory and thinking speed, or get rid of addictions (by modifying dopamine receptors).

Improving one's mental faculties though gene therapy might prove more difficult for a number of reasons.

1. It has proved quite difficult to identify genes for intelligence, because intelligence is a vague concept that can mean many different things. Is intelligence a gift for numbers, for words, for music, for social relationships, for drawing, for understanding mechanism ?
2. Intelligence doesn't depend only on genes, but also on a variety of other factors such as fetal development during pregnancy, the home environment and intellectual stimulation while being raised as a child, and so on.
3. Intelligence depends a lot on the effort and dedication spent to improve one's abilities. Furthermore, the more time one spends developing some abilities, the less is available for other abilities. That is why people who are extremely gifted in one field often lack in other fields.
4. The same is true of memory. Good memory requires regular practice, just like sports. And memory declines with age, or with smoking, fatty diet and many other environmental factors.

There are so many non-genetic factors involved in intelligence that even if we could raise a bit people's potential to learn and memorize, the world wouldn't suddenly be filled with geniuses. There would still be as much diversity as today, but with slightly more capable people in their respective fields of interest, which isn't a bad thing.

Considering the numerous non-genetic factors contributing to our intelligence and personality, there is no reason to believe that the widespread use of gene therapy for personal enhancement would create an overly uniformized society.

This doesn't mean we should all start modifying our genes right now. Very little is known about the function of the four billions base pairs in our genome. Only a few thousands have been conclusively linked with diseases or traits. It will take many more years, and probably decades before we fully understand the role and function of every polymorphism.

The genes regulating the brain are particularly complex and account for a substantial portion of our genome. At least a third of the approximately 20,000 different genes that make up the human genome are active (expressed) primarily in the brain. So while in theory it would be a good thing to raise the overall intelligence of humankind, not much can be done at the moment.

What can be done now, besides curing diseases, is to change simple traits like skin tone, eye colour, hair colour, hair curliness, and perhaps even reduce body fat or slightly ameliorate physical fitness. Changing the dopamine receptors (notably DRD2) and serotonin transporter (SLC6A4) could also cure or alleviate gambling addiction, nicotine dependence, alcoholism, ADHD and other conditions.

Theoretically we also have the knowledge to change one's blood type (see ABO blood group and disease resistance) and the HLA genes regulating the immune system. It may be harder to predict the effects of such changes on the body's biochemistry, so it should be done only in people with serious autoimmune diseases clearly linked to a specific HLA type (e.g. HLA-B27 is a major risk factor for ankylosing spondylitis).

To get an overview of what can potentially be fixed, enhanced or customized by editing our genes, check What physical or mental enhancements are possible through gene therapy ?