Defective Genes Detected That Cause Form Of Epilepsy

The discovery of two human genes that cause a form of epilepsy is expected to throw light on the nature of the disease as well as on the general principles by which the brain operates.

Epilepsy experts also hope that establishing a genetic basis for the mysterious and often alarming disease will help remove the stigma that often is attached to it. During epileptic seizures, patients’ limbs may thrash about, frightening observers so much that in past centuries they assumed the body was possessed.

At least one form of the disease now can be attributed to defects in genes that make a critical component of the electrical circuitry of brain cells.

The defective component probably delays the recharging process in nerve cells that have fired off an electrical message to their neighbors. The delay presumably interferes with the brain’s intricate timing pattern and somehow triggers the widespread lock-step firing of nerve cells that is the hallmark of an epileptic seizure.

Epilepsy, said to affect 2 percent of people at one time or another in their lives, is a disease in which many different causes lead to the same symptoms, a derangement of the neuronal timing process. Some forms of epilepsy are caused by damage to the brain from infection or trauma, but 40 percent of cases are thought to be genetic in origin.