By Lisa Spear
June 27, 2018
Scientists have figured how to use a form of the powerful gene-editing tool CRISPR to erase genetic traits normally associated with autism. It is technology that could one day revolutionize the therapies that treat autism and improve the lives of thousands of people who suffer from the developmental disorder, the researchers say.
CRISPR has been a game changer in the biomedical research world because of the ease and precision with which it can be used to alter the genetic code. A team of scientists in Texas used it to edit out genes associated with autism traits in mice and observed clear results: The animals stopped digging obsessively, their erratic jumping around the cages slowed to a halt and they became more calm, according to the study published in the monthly journal Nature Biomedical Engineering.
This technology might be years away from being tested on humans, but the results are promising, lead author of the study neuroscientist Hye Young Lee told Newsweek.
“I really want to give hope for patients and families. We are working on it, and they should not lose hope,” Lee said.
Lee, an autism researcher at the University of Texas Health Science Center at San Antonio, used a very thin needle to inject CRISPR-Cas9 into the brain tissue of mice, targeting the striatum, a region in the brain known to mediate habit formation.
CRISPR-Cas9 is made of just a few ingredients. The RNA, a nucleic acid present in all living cells, is like a messenger, a guide that allows a specific site on the genome to be targeted. It is used along with a bacterial enzyme, called Cas9, which acts like molecular scissors, cutting the DNA at an exact point.
After the procedure, the mice recovered for up to three weeks before the scientists analyzed their behavior to find significant therapeutic results. They saw a 30 percent drop in compulsive digging, and a 70 reduction in jumping, both indicative of autistic behavior.
“You could knock out disease-causing genes and actually see fairly significant behavioral changes,” said bioengineer Niren Murthy, who also worked on the study. A University of California, Berkeley professor, Murthy invented the CRISPR-Gold technique that was administered to the mice.
Autism is a relatively common developmental disorder that leads to a range of problems with social interaction and communication. About one in 59 children suffer from the condition, according to estimates from the Centers for Disease Control and Prevention. There is not one type of autism but many variations, caused by combinations of genetic and environmental factors. It can leave people with difficulty speaking and up to one third of autism patients are completely nonverbal, according to Autism Speaks, an advocacy organization in the United States.
Autism patients also tend to engage in repetitive behavior, like rocking back and forth and flapping their arms. The study suggests that these behaviors could be remedied through gene editing. These results could also open the door for further research on how to alter genes related to the other autism traits, said Lee.
“I really want to give hope for patients and families. It is such a social burden on them, and having the patients in the family affects the whole family,” she said. “We want to help them.”
The next step is to start testing this gene-editing technique in larger animals, like rats and then monkeys. It could be many years before scientists can safely use this method on humans, but the results are promising.
“I am optimistic about the future,” said Lee.