Cystic fibrosis. Hemophilia. Sickle cell disease.

Those are just a few of the thousands of genetic diseases that gene editing could cure. Several biotechs are already working hard to make it happen.

But as revolutionary as curing genetic diseases would be, other potential applications for gene editing are even more mind-boggling. Science fiction writers have envisioned the possibilities of genetic engineering -- both good and bad -- since at least 1932, when Aldous Huxley published Brave New World. With gene editing, science fiction just might become reality.

 

A digital globe next to a DNA helix

Image source: Getty Images.

What is gene editing?

The simple explanation of gene editing is that it's the insertion, deletion, or replacement of DNA (deoxyribonucleic acid) in a cell or organism. The process of editing genes isn't quite that simple, though.

Genes are sections of DNA that specify how proteins are built based on the unique sequence of four DNA bases -- cytosine, guanine, adenine, and thymine. These DNA bases are typically referenced by their initials: C, G, A, and T. The bases are always paired up in DNA, with adenine (A) across from thymine (T) and cytosine (C) across from guanine (G).

Gene editing involves changing the sequence of the DNA base pairs. For example, a sequence of A-G-C-A could be changed to A-G-C-T. Scientists accomplish this through one of several gene-editing techniques, including zinc finger nuclease (ZFN) technology. The most popular approach, though, is CRISPR, which stands for Clustered Regularly Interspaced Short Palindromic Repeats. With CRISPR, a DNA-cutting enzyme is used to slice a targeted section of DNA. 

Transforming the world

Many technologies are hailed as game-changing. Few actually live up to the hype. Gene editing, however, should be one of the exceptions. The future of life on planet Earth could realistically be changed in significant ways through the editing of DNA in genes.

What might the future look like? Here are five ways gene editing could transform the world.

1. Solving the organ transplant crisis

More than 35,000 transplants were performed last year. The good news is that's an all-time record high. The bad news, though, is that over 115,000 men, women, and children currently await an organ transplant. Every 10 minutes, another person is added to the list. Twenty people die each day waiting for a transplant. 

Researchers are getting creative at finding new donors. For example, in the past, organs from individuals with hepatitis C couldn't be used for transplants. Now, though, clinical studies are under way where patients on the transplant list are given organs from donors who have hepatitis C. After the transplant, they're given a drug such as Harvoni that cures the disease. So far, the experimental approach has been successful. 

But even innovative approaches like this one have their limits. Only three out of 1,000 deaths occur in a way that allows for organ donation. And only a little over half of U.S. adults sign up as potential donors.

One alternative is to transplant organs from pigs into humans. Pigs have hearts, livers, and kidneys that can be similar enough in size and in functionality to work in humans. One problem with using porcine implants, though, is that pigs have retroviruses -- viruses that have inserted part of their DNA into their host's DNA. These retroviruses could possibly harm humans. Also, human bodies could reject the organs transplanted from pigs.

Gene editing could address these problems, and in doing so, solve the organ transplant crisis. Researchers are attempting to use CRISPR to cut the retroviruses out of pigs' DNA. The possibility exists that DNA in pigs could even be edited so that humans won't reject the organs. 

2. Making pests less pesky

Mosquitoes can spread a grisly assortment of diseases. The deadliest of all is malaria. Up to half a billion people get malaria each year, with as many as 2.7 million deaths annually. Another mosquito-borne virus, dengue, affects around 390 million people each year, resulting in up to 25,000 deaths. 

But what if mosquitoes were physically incapable of carrying those diseases? Sure, they might still bite and be annoying. If they couldn't transmit disease, though, mosquitoes wouldn't be nearly as dangerous as they are today.

Gene editing to the rescue. Scientists have discovered that editing just one gene in mosquitoes makes the insects highly resistant to the Plasmodium parasite that causes malaria. Mosquitoes that can't be infected with malaria can't transmit the disease to humans. 

Dengue could be defeated by gene editing as well. Mosquitoes try to fight off the dengue virus with their own immune systems. Researchers think that CRISPR can be used to tweak the DNA in mosquitoes to turbocharge their immune responses to dengue virus infections. Again, a mosquito that resists infection won't be able to pass dengue along to humans. 

3. Creating superfoods

Genetically modified foods already exist. And they generate a lot of controversy. Big corporations market crops that are designed to be resistant to herbicides and insects. The genetically modified organisms (GMOs) used today primarily involve inserting a foreign gene into plants.

Imagine, though, fruit and vegetables that don't spoil at all and taste better. And crops that grow several times faster than they do today. Don't stop there, though: Envision plants that taste exactly like your favorite meat. 

Gene editing could be used to make all of this more than a pipe dream. Fruit and vegetables spoil because microorganisms cause them to do so. Their taste is dictated by their DNA. So is how fast they grow. Animals that are the primary sources for meat -- chickens, cows, and pigs -- basically convert plants into tasty foods for meat lovers. 

CRISPR could be used to modify the genes of fruit and vegetables to resist the microorganisms that result in spoilage. Scientists could use the gene-editing technique to target the specific sections of DNA that make apples and other fruit sweeter. And it's even possible that the DNA of plants could be altered to taste like meat in a way that goes way beyond veggie burgers. 

Not only could gene editing improve the foods that we eat, it could result in our diets being much healthier. A faux filet mignon that tastes just like the real thing and is good for you? That's a game-changer, in my view.

4. Resurrecting extinct species

The dodo bird went the way of the dinosaurs in the seventeenth century. Dinosaurs themselves became extinct around 65 million years ago. More recently, other animals have died out, including the Javan tiger, the Pinta Island tortoise, and the Western Black Rhinoceros. 

All of these animals are gone, but some of them don't necessarily have to be gone for good. No, it's not likely that gene editing will make Jurassic Park a reality. However, it could be used to resurrect some extinct species.

Woolly mammoth walking through a field with line of trees behind it

Woolly mammoth. Image source: Getty Images.

An extinct animal's genome -- its complete set of genes -- could be sequenced, which involves determining the exact order of the building blocks in DNA. The genome would then be compared to a related living animal with somewhat similar DNA. For example, a mammoth's DNA could be matched up to the DNA of an elephant.

Gene editing could then be used to modify the DNA in the embryonic cells of a related living animal. Next, the embryo would be put in a mother-to-be. Then it would just be a waiting game for a genetically engineered version of the formerly extinct animal to be born. 

5. Designing humans

Probably the most mind-blowing way that gene editing could be used in the future is to improve the homo sapiens species. This idea is also the most controversial possible application for gene editing of all.

Could "designer babies" really be possible? Using gene editing to alter the DNA of human embryos to possess specific traits isn't totally far-fetched. The level of difficulty hinges on how many genes cause the desired trait.

Eye color, for example, is controlled by a relatively small number of genes. Robin Lovell-Badge, a professor of genetics and embryology at the Francis Crick Institute, thinks that using gene editing to determine a baby's eye color could be achieved at some point in the future. 

Predetermining height would a much tougher challenge. Some scientists estimate that around 93,000 genetic variations influence a person's height. A study last year found that nearly 700 of them explain around 20% of the inherited component of height. (Nutrition and other factors also make a difference.) Modifying 93,000 -- or even 700 -- genetic variants would be much more difficult than altering only a handful.  

Still, the daunting obstacles of today could be overcome by innovations in the future. That's been the case with nearly every technological advancement.

Using gene editing to modify human beings, though, raises significant ethical concerns. Many people can accept the idea of fixing genes in babies to cure genetic diseases, but using CRISPR to design the next NBA basketball star is another matter altogether.

How can investors profit?

If a technology holds the potential to transform the world as we know it, you might wonder if there are ways to profit from it. There are. The table below identifies several companies that are pioneers in several of the five gene-editing applications of the future that have been discussed.

Company

Market Cap 

Primary Gene Editing Focus Area

CRISPR Therapeutics (NASDAQ: CRSP)

$2.5 billion Treating genetic diseases

DowDuPont (NYSE: DWDP)

$154.6 billion Creating superfoods

Editas Medicine (NASDAQ:EDIT)

$1.7 billion Treating genetic diseases

Illumina (NASDAQ:ILMN)

$35.6 billion Gene sequencing

Intellia Therapeutics (NASDAQ: NTLA)

$943.1 million Treating genetic diseases

Monsanto (NYSE:MON)

$55.2 billion Creating superfoods

Pacific Biosciences of California (NASDAQ: PACB)

$341.6 million Gene sequencing

Sangamo Therapeutics (NASDAQ: SGMO)

$1.7 billion Treating genetic diseases

United Therapeutics (NASDAQ: UTHR)

$4.8 billion Genetic engineering of animals for organ transplantation

Data sources: Google Finance, company news releases and presentations. 

Which of these stocks present the best options for investors? I especially like three of them.

Editas Medicine

Editas Medicine is a trailblazer in the use of CRISPR gene editing. The company is researching therapies to treat several genetic diseases, including Leber congenital amaurosis type 10, a genetic eye disease that leads to blindness in children. At this point, though, Editas doesn't have any programs in clinical development. The company plans to submit for approval in mid-2018 to advance its lead candidate into a phase 1 clinical trial.

A key advantage for Editas is that it licensed patents from the Broad Institute and Harvard College for use of CRISPR in eukaryotic cells (cells that have a nucleus). Since the cells of humans, animals, and plants are eukaryotic, if CRISPR is used in any of the gene-editing approaches discussed earlier, Editas should benefit. The patents licensed by the biotech have withstood one challenge in the U.S., although the European Patent Office revoked one of the patents earlier this year.  

Illumina

Illumina stands as the clear leader in gene sequencing. The company's technology paved the way for lowering the cost of mapping a human genome from $200,000 in 2009 to $1,000 in 2014.

There are several reasons for investors to like Illumina. The company launched a new system, NovaSeq, last year, that could eventually lead to a $100 genome. Illumina is rolling out a desktop gene-sequencing system this year called iSeq that costs less than $20,000 and could expand the market considerably. The company is also poised to profit from growth in consumer genomics services such as Ancestry, 23andMe, and Illumina's own spin-off, Helix.

Monsanto

Monsanto ranks as the world's leading producer of genetically modified seeds and crop protection products. The company continues to be a top innovator in the agricultural industry, with an impressive pipeline of projects to help farmers address threats to their crops including corn and soybeans that are highly resistant to weeds and disease and product to help honeybees fight off infection from Varroa mites. 

Warren Buffett is a big fan of Monsanto, recently increasing his stake in the company. It's not hard to figure out why. Monsanto enjoys a solid economic moat thanks to its extensive patent portfolio. With climate change increasing weather volatility, demand for Monsanto's products should grow in the future. The company isn't likely to be an independent entity for long, though: The U.S. Department of Justice has cleared the way for Bayer to acquire Monsanto. 

Brave new world?

Some of the ways that gene editing could transform the world might seem a bit scary and threatening. It could be disconcerting to have a pig's kidney transplanted to a family member. Do we really need to improve on Mother Nature by making fruit that doesn't spoil and meatless meat? Resurrecting animals that have been extinct for a long time is at least a little eerie. And designer babies could be a big step too far for many people.

The pre-eminent question, though, is much more "Should we?" than "Can we?" I suspect that in most of the scenarios, the answer is going to be that we should -- and we will. Gene editing seems destined to usher in a new world that has only existed thus far in the realm of science fiction.

Keith Speights owns shares of Editas Medicine. The Motley Fool owns shares of and recommends Illumina. The Motley Fool recommends Editas Medicine. The Motley Fool has a disclosure policy.