Gene

Gene Editing and CRISPR explained

ARYAN BANERJEE
Aug. 6, 2021

Gene Editing and CRISPR explained!

Alright, here's a go-to sci-fi storyline that just keeps on giving. Scientists mess around with DNA and then crazy things happen. You've got the classics like Jurassic Park (sci-fi movie), and then you've got The Rock's Rampage with a giant gorilla and a flying wolf with wings. But for me, I gotta go back in 1997 for Gattaca (movie), where society uses genetic testing to create designer babies with ideal genes. Late in 2018, the world of Gattaca, took a small step into the real world.

A Chinese researcher revealed that he created the first-ever genetically edited babies. He altered the DNA of the twin girls before they were born in what he says was an attempt to make them biologically resistant to HIV and AIDS In response, the world went kind of nuts, raising a huge bioethical question: When is gene editing okay? How far is too far when altering life itself?

Let’s talk about Genes

We can't talk about gene editing without first talking about genes, which are kind of like the instructions for life. All living things have them. They determine most of your physical traits like the color of your eyes, whether your hair is curly or straight, the density of your bones, even how your heart responds to exercise.

For thousands of years, humans have been unknowingly exploiting this in plants and animals through selective breeding. Every time a farmer decides to plant seeds from the biggest, juiciest tomatoes, to get bigger, juicier tomatoes, they were indirectly influencing genes. Selective breeding is why we have hundreds of different breeds of dogs. I mean, come on, Chihuahuas and Great Dane's are both the same species. Now that's crazy, that's a super-wide spectrum. Selective breeding works but it's imprecise and it takes generations before you see results. What if instead you could directly manipulate individual genes. That's exactly what gene editing does.

Role of Technology and CRISPR

The technology has been around for a couple of decades but it's only been in the last five or six years that gene editing has really taken off. That's because of CRISPR (Clustered regularly interspaced short palindromic repeats), one of the biggest scientific breakthroughs in decades. It's a gene-editing tool that can target specific genes allowing scientists to make precise edit much like a software engineer modifies code.

They can cut out a gene; they can modify a gene; they can add an entirely new gene. If you want to learn more about it, our friends at It's Okay to be Smart did a great video and you should definitely check it out. Now, every week there's news of another CRISPR breakthrough. One company is trying to turn pigs into organ donors for humans using CRISPR so that the human body doesn't reject foreign tissue. A team of researchers in Texas used it on puppies with a disease that causes severe muscle loss.

CRISPR essentially reversed the muscle loss, creating some pretty jacked beagles. There are even scientists using CRISPR to add genes from the long-extinct wooly mammoth into its closest living relative, the Asian elephant. They're basically trying to create a wooly mammoth, elephant hybrid that might be able to better tolerate climate change. Now that's some pretty Jurassic Park-level science if you ask me. But just because CRISPR might be able to do all this stuff one day, does that mean we should? If CRISPR delivers even a fraction of what we've been promised, it could be a game changer in how we fight diseases.

Take sickle cell disease, for example, where there aren't enough healthy red blood cells to carry oxygen throughout the body. It affects about 100,000 Americans and it's caused by a mutation in one gene among the roughly 20,000 found in humans. In fact, there are over 10,000 human disorders that are caused by single-gene mutations. What if CRISPR could cure all of them simply by fixing the mutation? CRISPR could also help prevent infectious diseases. Researches have been able to disrupt the reproductive cycle of mosquitoes- meaning they die off and can't transmit malaria, zika and other deadly viruses that kill hundreds of thousands of people, many of them children, worldwide every year. But things get really interesting when you think about how gene editing could affect multiple generations of humans. See, up until now, gene editing in humans has almost always been restricted to altering the genes in somatic cells. Which are the cells in the body that are not involved in reproduction. So any changes to DNA stay in that person, they can't be passed on.

The Chinese researcher who gene-edited those twins, did something different. He did his "CRISPR-ing" when the twins were still embryos, meaning the reproductive cells were altered. So, any changes can be passed down to future offspring. Now, that could be great. If the researcher was successful in introducing a biological resistance to HIV and AIDS, then maybe we could one day get to a place where we could cure disease in one generation and it disappears for all future generations.

Well, what’s the catch?

Now you're probably thinking what I'm thinking right now. All of this sounds too good to be true! What's the catch? Well, while CRISPR is a relatively simple tool, the effects of altering genes might not be. Scientists have recently learned that CRISPR has the potential to wipeout or rearrange largely chunks of DNA, which could do anything from turning off the wrong genes to triggering some forms of cancer. Also, who decides what's considered a problem. Does that need to be fixed? Sure, most of us might be fine with eliminating some diseases, but what about things like deafness or dwarfism or ADD?

Many people in those communities see their differences as positive and adding the human diversity, not as a problem that needs to be eradicated. And even if scientists can perfect gene editing, which is a big if, a Gattaca-style designer baby scenario isn't hard to imagine. The rich and powerful can shell out the big buck to customize their kids, protecting them from a bunch of diseases, reducing their risk for anxiety and depression, and maybe even giving them a heightened IQ boost. Meanwhile, the rest of us might only be able to afford a more limited amount of gene changes, if any.