The research, published in the prestigious journal Nature Genetics, proves the hereditary nature of a form of epilepsy previously believed to be caused by structural abnormalities such as a brain injury or a tumour.
Known as focal epilepsy it is the most common form, accounting for about 60 per cent of all epilepsies.
"Focal epilepsy was not previously thought of as being inherited and identifying this gene will help in the diagnosis and treatment of many people with epilepsy," UniSA’s Associate Professor Leanne Dibbens said.
"It is also particularly important for families to know more about why and how this kind of epilepsy occurs."
The research team from UniSA’s Epilepsy Research Program and UniSA colleagues from the Sansom Institute for Health Research working with experts from the Netherlands, Belgium, Germany, Israel, Canada, Melbourne, Adelaide and New South Wales detected the mutations in the recently discovered gene DEPDC5 on Chromosome 22, one of the smallest human chromosomes and the first to be fully sequenced.
"Previously genes for focal epilepsy have been identified for rare familial epilepsies but this new gene is also relevant to patients without a strong family history of the disorder," Assoc Prof Dibbens said.
She says a small proportion of people with abnormalities of this gene also have intellectual disabilities, psychiatric or autism spectrum disorders. The gene makes a protein that is found within nerve cells and appears to be important for signalling within cells.
"As we learn more about its function, and understand the epilepsies and other conditions associated with its malfunction, we hope it will lead to improvements in clinical care," she said.
"The discovery promises to change clinical practice.
"With what we now know, a genetic cause can be investigated in patients with focal epilepsy and, in cases where it is found, unnecessary other investigation can be avoided, accurate genetic counselling can be given and, in the future, there is a better knowledge base from which specific therapies can be developed to help people with epilepsy."