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It is now clear that most inherited epilepsies are benign and easily treated, and that the risk of having affected children is low. In an individual or family, accurate identification of the type of epilepsy syndrome now allows precise genetic counselling to be offered. Major molecular genetic advances can be realistically expected in the next five years. Such changes to our understanding of epilepsy will probably provide new avenues for therapy and perhaps even suggest strategies for prevention.

Understanding the causes of epilepsy is fundamental to improving treatment. An inherited component has been recognized since the time of Hippocrates, but the genetics have been poorly understood. Unfortunately, the fact that epilepsy may be inherited has added to inappropriate prejudice against people with epilepsy.

Until recently, progress was slow in this field and few researchers were working on the genetics of epilepsy. But there have been significant advances in the last few years. Two major developments sparked great interest. First, the clinical recognition that there are many identifiable epilepsy syndromes - some of which are inherited - and that there are genetic distinctions between them. Second, the revolution in molecular biology now allows researchers to identify the location and nature of genes that cause epilepsy. The promise is that identification of these genes will allow new insights into rational approaches to treatment.

Adapted from:
Genetics and Molecular Biology of Epilepsy
Samuel F. Berkovic, Austin Hospital, Heidelberg (Melbourne), Australia

Clinical research has resulted in the identification of a number of specific inherited forms of epilepsy. Two of the syndromes to be recognized so far are benign infantile familial convulsions, and autosomal dominant nocturnal frontal lobe epilepsy. The former begins at about six months of age and is associated with clusters of partial and secondarily generalized seizures. The family history may not be apparent unless carefully searched for. It is clinically and genetically distinct from the syndrome of benign neonatal familial convulsions, which characteristically begins around five days after birth. The importance of recognizing this syndrome is that it has a uniformly excellent outcome, so parents can now be counselled that their child will not have ongoing seizures.

Autosomal Dominant Nocturnal Frontal Lobe Epilepsy is a syndrome where motor seizures with tonic or hyperkinetic features occur exclusively at night. This disorder was frequently misdiagnosed as a variety of conditions including night terrors, other sleep disorders, or hysteria. Treatment with carbamazepine is usually highly effective.

Family studies of the more common epilepsies such as Juvenile Myoclonic Epilepsy and Absence Epilepsies have resulted in better understanding of the complexities of their genetics. It now seems likely that these epilepsies, like certain other common disorders with an inherited component, such as diabetes and hypertension, are caused by more than one gene. Special strategies now being developed will be needed to solve the molecular genetic problems posed by these genetically complex disorders.