A team of Australian researchers has come a step closer to unlocking a mystery that causes epileptic seizures in babies.

Benign familial infantile epilepsy (BFIE) has been recognised for some time as infantile seizures, without fever, that run in families but the cause has so far eluded researchers. However clinical researchers at the University of Melbourne and Florey Neurosciences Institute and molecular geneticists at the University of South Australia have discovered a gene.

BFIE is a disorder that occurs in previously healthy infants who are developing normally. Seizures commence when a baby is about six months old and stop by the age of two years. BFIE is a rare form of epilepsy with the Australian researchers having studied about 40 families from around the world. Some of the children with this gene abnormality develop an unusual movement disorder later in childhood or adolescence called Paroxysmal Kinesigenic Choreoathetosis (PKC).

This movement disorder causes sudden, brief stiffening or twisting of their muscles as the person starts to move, for instance, people with this condition often have difficulty crossing the road when the traffic lights change to green. While this condition can be easily controlled by medication, it impacts on quality of life and may prevent people from participating in some activities.

Families with this condition have now been found to carry a variation in a gene called PRRT2, which may cause the protein the gene encodes to form incorrectly. The function of this gene is not yet known nor is it understood how the changes in this gene cause an infant to have seizures. This gene discovery provides valuable opportunities for learning more about brain function and what causes seizures.

Professor Ingrid Scheffer, Chair of Paediatric Neurology Research said the finding would help families understand why their baby has seizures and will provide reassurance that the baby will grow out of the seizures and not have long term problems. It will also help with early diagnosis and appropriate treatment of the movement disorder.