Montreal researchers identify gene linked to autism, epilepsy

From The Montreal Gazette:

Researchers from Centre hospitalier de l'Université de Montréal Research Centre have identified a gene that predisposes people to both autism and epilepsy.

Led by neurologist Patrick Cossette, the team was looking for epilepsy genes when they discovered another connection in the complex genetic architecture of autism.

Cossette found a severe mutation of the synapsin gene (SYN1) in all members of a large French-Canadian family suffering from epilepsy, which included individuals with autism.

Results identify for the first time the role of the gene that is associated with both disorders, said Cossette, a professor in the faculty of medicine at the Université de Montréal. "The strength of the study is that we pinpointed the mechanism," he added.

Cossette's team went on to test two groups and identified the same mutation in one per cent of those with autism and three per cent in those with epilepsy. Several carriers of the SYN1 mutation had both disorders.

Several genes have already been linked with many forms of autism. An estimated one in 1,000 people suffer from a severe from of autism and about a third of them also have epilepsy. But until now the reason why these two diseases exist together has been a mystery.

The defect in both, explained Cossette, is a deregulation in the function of synapses and the communication process between neurons in the brain.

The synapsin gene plays a crucial role in the development of membrane surrounding neurotransmitters (chemical communication agents), which travel between two neurons.

The discovery is expected to open new doors in the understanding of brain pathology and offer a new focus for treatment.

The study was published in the online edition of Human Molecular Genetics.