New Gene Editing Method To Cure Genetic Diseases

Brian Madeux is 44-year-old man from Arizona and he is one of the oldest people still living with a disease called Hunter syndrome. Until now, he had 26 surgeries and the main goal was to help him stay alive. However, there is no cure for this illness. Now he takes part in a clinical trial conducted by California Company Sangamo Therapeutics. This company’s major goal is to find the ultimate cure for this illness and many other genetic diseases.

What is Hunter syndrome?

Hunter syndrome is a genetic disorder which affects human cells and slowly destroys them. It usually affects only boys. The body can't process a certain kind of protein, so those proteins build up in human cells causing damage to bones, tissues and, in the end, brain. Hunter syndrome usually affects body parts such as: large, round cheeks, broad nose, thick lips and a large tongue, bushy eyebrows, large head, slowed growth etc. The symptoms vary from person to person, but they are usually manifested as heart problems, breathing problems, trouble with walking, liver problems and a lot of coughs, sinus and throat infections.

The life expectancy with the disease is 10 to 20 years, so most patients are children. However, the trial is currently open only to adult patients. Young patients still need to wait for the official approval of this gene-editing method.

How does the therapy work?

Genetic diseases, caused by genetic mutations, are now treated symptomatically, which means that only their consequences are cured. This new treatment allows doctors to treat diseases from a completely different angle. Instead of curing consequences, they would cure the “ill” part of the human DNA.

Brian Madeux got billions of copies of a curative gene through an IV injection. The genetic tool will eventually improve his DNA material. The scientists programmed the virus to implant itself just into liver cells. By inserting it in just one part of the body, they will make sure that this virus won't do much damage in other parts. The virus will make copies of the ZFN protein and correct the genes that cause metabolic disorder, ABC reports say.

Madeoux said he was ready to take any kind of risk. We can expect some improvements in a month, and after three months the tests will give the ultimate answer. If successful, it will be a huge breakthrough in a new field of gene therapy.

Is this first human gene-editing?

Scientists have changed human genes earlier, but they did it in the lab, on the excised cells that they then returned to the patients. There are genetic therapies that do not include DNA modifications. However, these methods can only be used for several diseases. Some give results that are not durable. Others plug the new gene into DNA as a "reserve" but have no control where the gene will be injected, which can lead to other problems, such as cancer.

With this new method genetic modifications happen precisely within the body. It is about sending a miniature surgeon who sets the gene exactly where it is needed. This means there is no way back or ways to correct mistakes made by genes change. Experts believe that even though they can't predict all the risks, research studies will provide all the details to improve it in the future. These metabolic diseases have fewer than 10,000 people worldwide, partly because many die very young. Doses of missing enzymes can reduce some of the symptoms, but they cost between $ 100,000 and $ 400,000 per year and do not prevent brain damage.

Genetic modifications will not repair the damage already done, but they might minimize the risk for new ones. The ultimate goal of the research is to treat very young children, who did not suffer much damage. If successful, this American scientist's attempts to permanently change DNA and thus cure the disease could open the way for healing up to 6,000 to 7,000 genetic diseases that are caused by mutations in genes.

Source:

• http://www.abc.net.au/news/2017-11-16/us-man-undergoes-gene-editing-to-treat-rare-genetic-disorder/9157788