An anti-anxiety drug may reduce autistic features in a rare inherited disease, according to a new animal study published Wednesday in the journal Nature Communications.

In the study, researchers developed a mouse model of Jacobsen syndrome, a rare genetic disorder in which a child is born missing a portion of one copy of chromosome 11. About half of the children born with the inherited disease experience social and behavioral issues consistent with autism spectrum disorders (ASDs). Patients with Jacobsen syndrome also face multiple health challenges, such as congenital heart disease, intellectual disability, and developmental and behavioral problems.

The mouse models were designed to exhibit autism-like social behaviors, and were used to decode the molecular mechanism that connects the genetic defect inherited in Jacobson syndrome to effects on brain function.

"While this study focused on mice with a specific type of genetic mutation that led to autism-like symptoms, these findings could lead to a better understanding of the molecular mechanisms underlying other autism spectrum disorders, and provide a guide for the development of new potential therapies," study co-author Dr. Paul Grossfeld, a clinical professor of pediatrics at UC San Diego School of Medicine, and pediatric cardiologist at Rady Children's Hospital-San Diego, said in a news release.

Researchers determined that PX-RICS— which previous research suggested may be the missing chromosome 11 gene— is most likely the gene responsible for autism-like syndromes in Jacobsen syndrome. They also found that mice lacking in PX-RICS were also deficient in a protein crucial for normal neuron function, GABAAR.

Based on this, researchers tested clonazepam, an anti-anxiety drug, to see whether it treated autism-like symptoms in the Jacobsen syndrome mice by boosting GABAAR. They observed that PX-RICS-deficient mice treated with low, non-sedating doses of the drug behaved almost normally in social tests, experienced improvements in learning performance and were better able to deviate from established habits.  

"We now hope in the future to carry out a small pilot clinical trial on people with Jacobsen syndrome and autism to determine if clonazepam might help improve their autistic features," Grossfeld said in the release.

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