Last month, a man with a debilitating genetic disorder underwent a potentially life-altering procedure that is being touted as the first of its kind.
The treatment involved editing his genome.
The man in question has Hunter syndrome.
The ailment is caused by a missing or malfunctioning enzyme, according to the Mayo Clinic.
With Hunter syndrome, a person doesn’t have enough of the enzymes that break down certain molecules.
This causes the molecules to build up and cause harm.
The result is progressive damage that affects a person’s appearance, mental development, organ function, and physical abilities.
The doctors who treated this man don’t expect to rid him of the disorder, but they do hope that the treatment will provide some relief.
Genetic engineering put to use
For decades, scientists have been touting the benefits of genetic engineering.
But it’s only in the past few years that the technology has started to catch up with theory and hypothesis.
Practical application of gene therapies for real-life treatments are still few and far between, which explains the significance of the Hunter syndrome case.
Yet scientists are making breakthroughs in laboratory research, with new findings published in scientific journals nearly every month.
“We’ve been gene editing for my entire career, but we’ve got better and better,” Lawrence Brody, PhD, senior investigator at the Medical Genomics and Metabolic Genetics Branch at the National Human Genome Research Institute, told Healthline.
In August, an Oregon research team successfully edited genes in human embryos to repair a serious disease-causing mutation. The treatment produced a healthy embryo, according to a in the journal Nature.
In early December, researchers at the Salk Institute in San Diego successfully activated “good” genes in live mice suffering from dystrophy, type 1 diabetes, and acute kidney injury, according to the Los Angeles Times. More than 50 percent of these animals showed improved health.
Gene editing, in the simplest terms, works by removing the part of the cell’s DNA that causes a health issue and replacing it with DNA that won’t.
“It’s going into somebody’s cells and precisely modifying the DNA at a specific location of your choice,” Douglas P. Mortlock, PhD, a research assistant professor at the Vanderbilt Genetics Institute, told Healthline. “That’s gene editing.”
Mortlock also co-authored a statement on germline genome editing for the American Society of Human Genetics.
Using a virus as a transport
In the case of the man with Hunter syndrome, the doctors turned to a gene editing protocol called zinc finger nuclease.
The technique calls for a new gene and two zinc finger proteins to be placed in a virus that doesn’t cause infection.
The virus is injected into the body, carrying the components to the various cells. The fingers then “cut” the DNA, which allows the new gene to attach to that DNA and do the work it’s designed to achieve.
In the Hunter syndrome case, it was the first time scientists have tried editing a gene inside a person’s body.
As impressive as that sounds, both Mortlock and Brody think another gene editing protocol works even better.
The technology known as CRISPR has helped scientists make significant headway in the field of genetic engineering.
The term is an acronym for Clustered Regularly Interspaced Short Palindromic Repeats.
Brody said that CRISPR makes it easier for scientists to conduct gene editing research for a host of reasons.
One of the most important aspects is that the technique doesn’t rely on proteins — as in the case of zinc finger nuclease — to do the hard work.
Instead, CRISPR employs the use of RNA, which has the capability to provide more precise and targeted replacement than protein strands.
“CRISPR is much more efficient,” Brody said.
Matlock said up into the early 2000s, gene editing was difficult to achieve. CRISPR has made it much easier for scientists to conduct their research.
“In 2011, I didn’t know what CRISPR was,” he said. “In 2013, I mutated mouse embryos with CRISPR.”
In 2017 alone, CRISPR is responsible for a host of breakthroughs inside research labs.
The technique has allowed scientists to remove HIV from a living organism. It’s also helped scientists find the “command center” of cancer and make viruses that force superbugs to self-destruct.
That’s just the tip of the iceberg.
Both Brody and Matlock say in the future gene editing will have a role in treating sickle cell anemia, hemophilia, and muscular dystrophy.
But the practical applications aren’t ready for their debut.
It’s going to take years of consistent research and most likely new gene editing techniques that have yet to be uncovered.
“People are working hard to find CRISPR 2,” Matlock said.