New genetic cause for rare form of epilepsy identified

An international research team that includes the University of Melbourne’s Professor Sam Berkovic (AC) has identified a new gene for a progressive form of epilepsy.

The findings of this international collaboration have been published today in Nature Genetics.

Progressive myoclonus epilepsies (PME) are rare, inherited, and usually childhood-onset neurodegenerative diseases whose core symptoms are epileptic seizures and debilitating involuntary muscle twitching (myoclonus).

Professor Berkovic said this finding of a new gene underlying progressive myoclonus epilepsy is one of the most devastating forms of epilepsy.

“For the study, we used modern DNA sequencing technologies, which have revolutionised genetic research of rare, severe diseases, “Professor Berkovic said.

“It showed a single mutation in a gene explains a significant proportion of unsolved PME cases. The new mutation identified in the study disrupts the function of a pathway that has a central role in signal transmission in the brain,” he said.

The likely consequence of the mutation is that signals in certain parts of a patient’s brain are reduced, which makes patients susceptible to epileptic seizures and involuntary muscle twitching starting in childhood.

The mutation also causes degeneration of the cerebellum and subtle cognitive decline in some of the patients.

Findings of the study shed light on the molecular genetic basis of progressive epilepsy that may lead to potential new treatments for the disease.

Researchers of the project emphasise the importance of international collaboration for the study.

Professor Berkovic coordinated the patient sample collection spanning 20 years and involving multiple epilepsy centres worldwide.

“This study shows the power of combining sample collections and knowledge from different countries”, he said.

(Source: The University of Melbourne, Nature Genetics)