Genomic editing to save lives

This is a photo of DNA is contained in all cells, such as these ones obtained from this inside of a human cheek.

DNA is contained in all cells, such as these ones obtained from this inside of a human cheek.

Senior Jeffrey Mullen’s morning routine entails a shower, breakfast and a vest shaking him for half an hour to loosen the mucus in his lungs.
This is just one of the many treatments necessary to treat his cystic fibrosis (CF), a rare condition caused by a genetic mutation that primarily affects the lungs, but also the liver, kidneys, pancreas and other intestines. In addition to frequent coughing up mucus, Mullen is also highly susceptible to lung infection which has been cause for fairly frequent hospitalizations.
“Usually when I’m hospitalized, I’m forced to do a treatment four times a day,” Mullen said. “I’m required to do an inhaled antibiotic every singletreatment, [and] I have to do physical therapy. I always have to get a PICC [peripherally inserted central catheter] line. Think of it like a super IV.”
For people such as Mullen who suffer from genetic disorders, a new technology known as CRISPR (pronounced “crisper”) provides the potential to permanently rid them of their ailments. CRISPR stands for clustered regularly interspaced palindromic repeats and is a part of the immune system of bacteria.
In 2012, Jennifer Doudna, a Berkeley biologist, discovered that when paired with a molecule called Cas 9, it could be used to edit human, animal, and plants cells. Although gene editing is not entirely new, CRISPR is revolutionary because it it cheaper, faster and more accurate than previous gene editing technologies.
CRISPR has been used in food science where it helped create mushrooms that don’t brown. Research is currently underway that focuses on using CRISPR to treat HIV, cancer, and genetic disorders among other non-human uses according to the FDA. The technology has already been successful in correcting a mutation that causes hypertrophic cardiomyopathy, a dangerous heart condition.
However, there has been hesitancy to be begin clinical trials, as CRISPR has the potential to edit a gene that is not the target, a mistake that could prove dangerous or even fatal to a human subject. Jordan Kuhnert, a sophomore who is taking human body systems and is interested in pursuing a career in medicine, has concerns about this technology as well. Although it is promising, she believes it is not quite ready for a mass market.
“We are still many years away from CRISPR becoming a generic and widely available treatment,” Kuhnert said. “There are many things that scientists don’t know about CRISPR and what it could do. Professionals worry that it could introduce new mutations into the human genome that have never been seen before. This, in turn, could cause a whole new set of problems.”
In China, clinical trials have already begun, with more than 80 patients having received treatment for HIV and several types of cancer. There are fewer governmental restrictions on clinical trials, with the focus being on technological advancement, allowing China to race ahead in terms of genomic editing.
Dr. Meredith Triplet is a scientist working on CRISPR research projects with Jennifer Doudna. In an interview, she commented on the obstacles delaying CRISPR clinical trials in the United States.
“Different cultures and countries have different regulatory policies and norms, so CRISPR will be applied in different countries at different rates,” she said. “Different groups of people have different value systems and risk-tolerances which lead to different conclusions about when, why and how to apply new technologies. Researchers in China have used CRISPR to edit non-viable human embryos, where such research has not been done in the US. However, researchers in both countries are actively pursuing new techniques and ideas that will enable CRISPR to have a positive impact on the human condition.”

This is a photo of DNA is contained in all cells, such as these ones obtained from this inside of a human cheek.
DNA is contained in all cells, such as these ones obtained from the inside of a human cheek. Photo by Amanda Kurukulasuriya
Currently, United States’ researchers have tested on monkeys, which are touted as ideal test subjects because of their genetic similarity to humans. The treatment may provide a solution to sickle-cell anemia and beta thalassemia, both of which are caused by a mutation in a gene that creates hemoglobin, a protein necessary to transport oxygen through the body.
In Europe, the biotech company CRISPR Therapeutics is looking to get the go-ahead for a project that would test the technology on human sickle-cell patients. Meanwhile, a  company called Editas Medicine plans to get approval from the United States Food and Drug Administration this year to begin trials on humans to treat Leber congenital amaurosis, a genetic disorder than causes blindness.
“I think CRISPR will provide an option for the treatment of genetic disorders, such as sickle-cell disease, Huntington’s disease, and others, as well as a treatment option for cancer and immune disorders,” Triplet said. “However, it will be some time before these treatments make it all of the way to market. I expect we’ll start seeing some CRISPR-based treatments available in the next decade or so, and more will follow later after that. It will be a long time before we can fully apply the promise of CRISPR.”
For people like Mullen, CRISPR could be life-changing. The average life expectancy of people with cystic fibrosis is 37 years, 41 years fewer than that of the average American. And although this number increases every decade, in 2016, the Cystic Fibrosis Foundation Patient Registry found that over half the people with CF that died that year had died before the age of 30. As of now, CF, like many genetic disorders, has no known cure. Mullen, however, lavishes in the shorter-term effects of not having the condition.
“I wouldn’t have to take special medicines,” he said. “My immune system would be better. I wouldn’t cough up anything… it sounds pretty nice.”