Dr Lynette Sadleir
"The work that we're doing is a bit of a first in New Zealand and will be important in our overall understanding of epilepsy," she says.
"Once epilepsy tended to be considered as a single neurological condition, but over the last two decades, because of research, closer observation of seizures and the advent of genetic analysis, we've realised that there are many different types of epilepsy often associated with different genetic abnormalities."
The first gene to be linked to epilepsy was identified only about a decade ago. Now about 14 have been uncovered, but these all relate to rarer forms of the disorder.
The challenge for Sadleir and other researchers is to determine which genes, and which combination of genes, can be linked to the more common forms of epilepsy in childhood. It is estimated that around 4000 New Zealand children have epilepsy and about 11 die every year.
"The reason the push is on is because identification of abnormal genes related to the more common forms of epilepsy in children is going to radically assist clinicians, like myself, to quickly determine the best treatment for infants, and their prognosis.
"We can often spend huge amounts of time and money trying to work out which form of epilepsy we're managing in an effort to improve treatment."
One example is Severe Myoclonic Epilepsy of Infancy (or Dravet syndrome) in which otherwise normal infants present with long seizures with fever at six months. If the syndrome is not identified early, and treated appropriately, these children do not develop normally and have a significant mortality rate.
Previously, the diagnosis was made by the exclusion of the many other aetiologies of epilepsy in this age group, which required expensive and invasive investigations. Since the recent discovery that this disorder is caused by a sodium channel mutation, it is now possible to quickly make the diagnosis with a simple blood test.
Sadleir is investigating as many families as possible with multiple individuals who have had seizures in order to describe more accurately their epilepsy.
If there is an identified inheritance pattern and there are enough family members affected, the family's blood undergoes genetic analysis by molecular genetic collaborators in Australia for abnormal genes that can be linked to that family's particular syndrome.
"In some cases we're characterising up to 40 members of an extended family to track down genetic changes. This means the two-year research project will cover at least 220 individuals, including the children."
Sadleir says the exciting thing about this research is that there is so much of the iceberg to be uncovered, which will result in much better treatment for children with a disorder that affects their schooling and their lives.
FUNDING
Health Research Council