Publishing in Nature, scientists in China announced they’ve genetically modified monkeys to develop symptoms associated with autism, in hopes of discovering treatments for the condition.

The scientists engineered the macaques by mutating their MECP2 gene. Such a mutation can result in MECP2 duplication syndrome, which shares a variety of symptoms with autism spectrum disorders.

“As compared to wild-type monkeys, MECP2 transgenic monkeys exhibited a higher frequency of repetitive circular locomotion and increased stress responses,” the researchers write. “The transgenic monkeys showed less interaction with wild-type monkeys within the same group, and also a reduced interaction time when paired with other transgenic monkeys in social interaction tests.”

Further, the researchers found that the monkeys pass on the genetic defect to their offspring.

The Guardian reports that a group of 200 monkeys has already been established in a lab in China.

“These results indicate the feasibility and reliability of using genetically engineered non-human primates to study brain disorders,” the researchers write.

According to the Centers for Disease Control and Prevention, about one in every 68 children is identified with an autism spectrum disorder. Doctors are usually able to diagnose a disorder successfully by age 2. Often, those diagnosed have problem with social, emotional, and communication skills. Though no cure exists, early intervention can help a child learn a variety of important skills.

“The first cohort of transgenic monkeys shows very similar behavior to human autism, including increased anxiety, but most importantly, defects in social interactions,” said the Institute of Neuroscience in Shanghai’s Zilong Qiu to The Guardian. “We are currently carrying out brain imaging studies and trying to identify the deficiency in brain circuits that is responsible for autism-like behavior.”

Doctors and scientists are still attempting to understand the root causes of autism. According to The Wall Street Journal, researchers have identified 65 genes that may contribute to the disorder. Additionally, 11 different strains of genetically engineered mice have been developed for study.

“For understanding the human brain, we better have an animal model with a brain very close to the human brain,” said Mu-ming Poo, who is the director of the neuroscience institute, to The Wall Street Journal. “We think a nonhuman primate is absolutely required in the long run for development of drugs for human psychiatric diseases.”