Rett Syndrome, a severe form of autism that occurs almost exclusively in girls, affects an estimated 1 in 8,500 females. Though rare, the debilitating disease causes severe problems with language and communication, learning, coordination, and other brain functions. 

According to the science journal Proceedings of the National Academy of Sciences, Penn State researcher, Gong Chen and his team have discovered a “novel drug target and have rescued functional deficits in human nerve cells derived from patients with Rett Syndrome, a severe form of autism-spectrum disorder.”

The researchers examined the nerve cells of patients with Rett Syndrome and discovered that they carry a mutation of the gene MECP2. Such gene mutations are believed to cause most cases of the disease. They also discovered that the nerve cells are missing an important molecule, KCC2, which is critical for normal nerve cell function and brain development.

“KCC2 controls the function of the neurotransmitter GABA at a critical time during early brain development,” Chen said. “Interestingly, when we put KCC2 back into Rett neurons, the GABA function returns to normal. We therefore think that increasing KCC2 function in individuals with Rett Syndrome may lead to a potential new treatment.”

In addition, Chen’s team also found that treating the diseased nerve cells with insulin-like growth factor 1 (IGF1) helped increase the level of KCC2, and eventually the GABA neurotransmitter returned to normal functioning. 

Researchers tested the IGF1 treatment on a mouse model of Rett Syndrome, and it proved to alleviate the symptoms. The treatment is now the subject of a phase-2 clinical trial for the treatment of the disease in humans. 

This discovery opens the possibility of finding other molecules, like IGF1, that can boost the KCC2 level to treat Rett Syndrome, and hopefully other autism spectrum disorders in the future.