One-third of children who have autism spectrum disorder also have epilepsy. It's related to a major autism risk gene, which is mutated in patients with autism. But scientists didn't now why the mutation, catnap2, caused seizures.
Now Northwestern Medicine scientists have discovered the mutation acts like a bad gardener in the brain. It shrinks the neurons' tiny branches and leaves – its dendrite arbors and synapses—that enable brain cells to relay vital messages and control the brain's activity. The shrinkage causes a breakdown in message delivery.
An important message that gets lost? Calm down!
In people with the mutation, inhibitory neurons—whose job is to keep things tranquil in the brain and slam the brake on excitatory neurons—don't grow enough branches and leaves to communicate their Zen-like message, the scientists found. That leads to seizures.
The mutation, CNTNAP2 or "catnap2," works as a team with another mutated gene, CASK, implicated in mental retardation. As a result, scientists have a new target for drugs to treat the disorder.
The paper was published April 2 in Molecular Psychiatry.
Journal reference: Molecular Psychiatry
