MAE belongs to a large group of idiopathic generalised epilepsies referred to as GEFS+ (Generalised Epilepsies with Febrile Seizures Plus). Disorders associated with GEFS+ are inherited or genetic so there may be, but not always, a family history of seizures. Most epilepsies in this group are usually outgrown in childhood, relatively benign or easy to treat. Within the GEFS+ spectrum, more severe and complex syndromes can occur including MAE and Dravet's Syndrome (SMEI or Severe Myoclonic Epilepsy of Infancy).
Some of the epilepsy types associated within the wide GEFS+ spectrum include:
• febrile seizures (FS) where seizures with fever or high temperature occur. FS affect 3% of ALL children, commonly outgrown by the age of 6 with low risk of epilepsy in later life.
• febrile seizures plus (FS+) where febrile seizures continue beyond 6 years of age sometimes interspersed with afebrile seizures occur.
• FS+ and absence seizures
• FS+ and myoclonic seizures
• FS+ and partial seizures
• Myoclonic-astatic epilepsy (MAE or Doose Syndrome)
• Dravet's Syndrome (SMEI or Severe Myoclonic Epilepsy in Infancy)
Several genes responsible for epilepsy in the GEFS+ group have already been identified. At present, this is largely research except in the case of SMEI (Dravet's Syndrome) where a diagnostic test to identify the gene SCN1A has been developed which can help confirm clinical findings and lead to better management of the disorder.
The genetics of MAE are still not fully understood. We know that it is polygenic meaning more than one gene is responsible for the disorder but we don't know how many genes. It is likely that mutations (or defects) of several genes have a combined effect to result in MAE. It is expected that in years to come, the genes responsible for MAE will be identified and this will help confirm a diagnosis, target medications and treatments leading to better management and improved outcomes for our children. One day it may even possible to switch off these faulty genes.
To learn more about GEFS+ please see the following link: