Gene editing is already a reality: scientists have invented a way to remove diseases from human DNA

According to scientists, the era of therapeutic editing of human genes is not just coming, but it has already come. We are not just waiting for the treatment of diseases, but the removal of them from our DNA, reports CNN.

Photo: Shutterstock

When popular YouTube star Adalia Rose died earlier this year, she looked like a petite, sickly woman in her 80s. In fact, she was only 15 years old, a victim of progeria, an extremely rare genetic disease caused by a single mutation in one of the 3 million base pairs that make up human DNA. Completely normal in mind and spirit, children with progeria age very quickly, usually dying in adolescence.

Rose has won the hearts of her over 3 million YouTube followers and 12 million Facebook followers with her fun, positive outlook and zest for life. With the help of her mother, she shared the details of her debilitating illness through upbeat, adorable videos while leaving plenty of room for her dance routines and numerous makeup tutorials.

“I look sexy!” she told her audience, tossing her blue-tipped blonde hair over her shoulder in Lizzo fashion before sitting down to explain to her viewers what medications she was taking and why she lost sight in one eye.

While Rose spent her short life helping to break the stigma associated with a devastating disease, geneticist David Liu dedicated his career to developing ways to change the genetic code that took Rose's life at such a tender age.

“That a single mistake in her DNA ended Adalya’s life so early is a loss for all of us,” said Liu, a professor of chemistry and chemical biology and director of the Merkin Institute for Transformative Health Sciences at Harvard University.

On the subject: If you want to live longer - drink more coffee: studies have found the healing properties of the drink

“I did not have the opportunity to meet Adele before she passed away. But every progeria patient I have met has been warm, charming, articulate, and deeply inspiring,” Liu said.

At their Harvard lab, Liu and his team have come up with new ways to repair mutated genes that do less damage to DNA than previous technologies. One of his lab's innovations is called a base editor, which he used last year to treat progeria in mice. There are four bases in DNA: adenine (A), cytosine (C), guanine (G), and thymine (T). They form certain pairs: A with T and G with C.

Liu hopes that the tool will soon be used in human clinical trials to treat progeria in humans.

“The database editor goes into the cells of the animal, looks for the error, which in progeria is the transition of the letter C to the letter T, and changes the letter T back to the letter C,” Liu said at the Life Itself conference on health and wellness. - And it's all. "We never go back to the patient—it's a one-time treatment that permanently eliminates the mutation that causes the disease."

Six months after announcing a successful treatment for progeria, Liu and scientists at St. Jude Children's Research Hospital announced that they had used base editors to treat sickle cell anemia in mice.

“The era of therapeutic editing of human genes is not just coming. It's already here," Liu told the Life Itself audience.

Advantage

Scientists edit genes with enzymes specifically designed to target a specific DNA sequence, cut out damaging genetic material, and insert replacement DNA. For decades, however, known methods for modifying our genetic code have been clumsy, often failing to achieve their goal or cutting out too much or too little genetic material.

The advent of CRISPR systems in the 1990s, and in particular CRISPR-Cas-9 in 2013, heralded a new, more elegant way to edit genes. CRISPR uses what is called guide RNA to direct the Cas-9 enzyme to a more precise location on the DNA strand to make the cut.

After several years of review, the US Food and Drug Administration approved CRISPR-Cas-9 in 2021 for use in human clinical trials for sickle cell anemia. Clinical trials are also underway to test the safety of gene editing in a blood disorder called beta thalassemia, Leber's congenital amaurosis, which is a form of hereditary childhood blindness, blood cancer, leukemia and lymphoma, type 1 diabetes, and HIV/AIDS.

In 2021, researchers reported that they had successfully treated a rare disease condition called transthyretin amyloidosis in six people with a single treatment. The deadly disease causes a protein called TTR to fold into clumps and attack the heart and nerves. A study published in August reported that TTR levels in some people decreased by an average of 87% after treatment.

However, like older editing technologies, CRISPR-Cas-9 cuts both strands of DNA, which has some drawbacks, Liu said. First, he said, some cells were reverting changes after they were made, "so the overall editing efficiency was very low."

Liu's team found that if you cut just one strand of the DNA double helix with CRISPR-based technology and "cut" the other, the cell is more likely to implement the corresponding change in the second strand without complaining and with fewer errors.

Editing large DNA sequences

Liu and his team also invented another type of CRISPR-based tool called a primary editor that could make larger, more complex changes to DNA that basic editors couldn't.

In tests using lab-grown human cells, Liu's team used primary editing to fix the genes responsible for Tay-Sachs disease, a deadly neurological disorder that strikes in the first few months of life. Children with Tay-Sachs disease usually die within a few years of the onset of symptoms.

“The analogy I like to use is that the original CRISPR-Cas_9 is like scissors cutting DNA. Basic editors are like pencils that precisely correct letters by replacing them with one of four different letters, Liu explained. “And basic editors are like molecular word processors that do true search and replace for large sequences.”

Only a third of the 75 known "spelling errors" that cause genetic diseases can be corrected by basic editors, Liu said. "But throw in our editor-in-chief, and together they can finally free us from responsibility for the vast majority of spelling errors in our DNA," he told a Life Itself audience.

“We have to make sure that all these different technologies go through very thorough clinical trials,” Liu added. “But if they prove safe and effective, we could imagine treating not only the rare misspellings that cause severe genetic diseases, but perhaps even treating gene variants that we know contribute to terrible diseases like Alzheimer's or high blood pressure.” cholesterol level."

You may be interested in: top New York news, stories of our immigrants, and helpful tips about life in the Big Apple - read it all on ForumDaily New York.

In a 2019 blog post, former director of the National Institutes of Health, Dr. Francis Collins, called the primary edit "revolutionary", stating that Liu and his team "used their new system to insert new DNA segments up to 44 letters long and remove segments of at least 80 letters." length."

However, Collins added: "It is not clear whether primary editing can insert or remove DNA the size of a full-length gene, which can contain up to 2,4 million letters."

Genetic editing will not be the solution to all life's ills, Liu warned. For example, infections and cancer cells are two areas that are not well suited for gene editing because you would need to touch each cell to stop the disease.

Read also on ForumDaily:

A 100-Year-Old Spa: Why You Should Visit Arkansas Hot Springs

No more killing animals: the world's largest factory for the production of artificial meat is being built in the USA

What Medicare Covers: 14 Little-Known Free Services That Can Help You Save Money and Prevent Health Problems

Do you want more important and interesting news about life in the USA and immigration to America? — support us donate! Also subscribe to our page Facebook. Select the “Priority in display” option and read us first. Also, don't forget to subscribe to our РєР ° РЅР ° Р »РІ Telegram  and Instagram- there is a lot of interesting things there. And join thousands of readers ForumDaily New York — there you will find a lot of interesting and positive information about life in the metropolis.