The Reporter: June 1995, Vol.6, No.3
Research Notes

Team Identifies Genetic Link For Form of Epilepsy

In what is being hailed as a breakthrough discovery, CPMC researchers have found a genetic link for partial epilepsy-the most common form of the disorder. Partial epilepsy, in which seizures begin in a specific brain region, has long been thought to result most often from head injury, vascular disease, or errors in brain development, not genetics. The finding is the first clue that genetics could play a role in partial epilepsy and ultimately may lead to improved diagnosis and a better understanding of the development of the disease.

Principal investigator Dr. Ruth Ottman, associate professor in the Gertrude H. Sergievsky Center and the School of Public Health, and colleagues described localization of a gene for partial epilepsy to chromosome 10 in the May 1 issue of Nature Genetics.

At some time in their lives, about 10 million Americans suffer from epilepsy, a common neurological disorder that causes symptoms ranging from recurrent convulsive seizures involving all or part of the body to momentary spells of impaired consciousness. Sixty percent of them have partial or localization-related epilepsy, which is characterized by seizures that emanate from a specific brain region and sometimes begin on one side of the body. Partial epilepsy is one of two broad types of epilepsy. The second type is generalized epilepsy, which is thought to involve the entire brain from the start of the seizure and is considered to be genetic in most cases. Several genes have been mapped for generalized epilepsy, but this is the first genetic link for partial epilepsy.

"While this finding will not immediately impact on prevention or treatment options for people with epilepsy, it is an important conceptual development," says Dr. Timothy Pedley, a coauthor of the paper and director of the Comprehensive Epilepsy Center at CPMC. "Until now most people have assumed that, with the exception of some childhood epilepsies, partial epilepsies as a rule were not genetic. In other words, partial epilepsy was considered an acquired disorder. Now we know that may not be true in all cases."

In an ongoing study of genetic contributions to epilepsy, Dr. Ottman's team collected information on seizure disorders in the families of nearly 2,000 adults with epilepsy. The team identified a family in which individuals in three successive generations are affected with partial epilepsy in a pattern strongly suggestive of a genetic link. The gene that may be responsible for epilepsy in this family was localized to chromosome 10. By identifying the area on chromosome 10 where a gene or genes responsible for partial epilepsy may exist, Dr. Ottman's team has succeeded in demonstrating a genetic cause in at least some cases of partial epilepsy.

"Because our analysis was restricted to a single family, we cannot estimate the proportion of familial epilepsy that can be attributed to this susceptibility gene," says Dr. Ottman. "However, even if the mutation found in this family is rare, the identification of its product and its effect may have important implications for determining what is causing the epilepsy."

Eleven individuals in the family developed the disorder between ages 8 and 19. They have similar seizure types and six report hearing a ringing or humming sound that steadily grows louder before seizures. Partial epileptic seizures often are preceded by a warning such as a sound or the twitching of an arm or a leg on one side of the body. The seizure that follows may be confined to one part of the body or spread to include the whole body.

While most members of the family who carry the gene developed the disease, some family members with the gene have not developed the disease. This suggests other things, such as environmental factors or another gene, may be required for the gene to cause epilepsy.

"We don't know why some people escape being affected," says Dr. Ottman, "but this would be an exciting area to study to get clues on how we might prevent the disorder in the future."

New Fire Alarm System Being Installed At P&S

A new state-of-the-art fire alarm system is being installed in the P&S building, reports Frank Calcagni, project coordinator for the Health Sciences Design and Construction Department. The coded system will use electronic beeps instead of bells, visual strobes, and a public intercom system to facilitate communication to each floor.

"To me, a public address system is a better type of fire alarm system, so if you do have a problem within the building, you can get the information to everyone at that point and time," says John Murphy, fire safety officer with the Health Sciences Office of Environmental Health and Safety.

New fire alarm pull stations will be lowered to meet the requirements of the Americans with Disabilities Act, Mr. Murphy says. The new visual strobes will help the hearing impaired in an emergency.

Mr. Calcagni expects minimal inconvenience to office and lab personnel in P&S as technicians install the system.

"Most of the work will be done in the staircases and corridor ceilings and walls," Mr. Calcagni says. "Some of the work may affect certain rooms. We will notify people who might be inconvenienced in advance."

Meanwhile, plans are under way to install a similar fire alarm system in the Black Building, starting early this summer. Both buildings should have new systems operational by the end of this year.