Genetic defect in human epilepsy

In a research published in the advanced online publication of the scientific magazine Nature Genetics, researchers have identified a genetic defect for common epilepsies on chromosome 15.

A subset of the patients with epilepsy lacked a certain part of this chromosome. Further studies on patients from the USA confirmed this finding. The loss of small chromosomal segments, called microdeletions by geneticists, has previously not been connected with common disorders that also include many types of common epilepsies.

Dr. Ingo Helbig, University of Kiel and Department of Neuropediatrics at the University Medical Center Schleswig Holstein, Germany, is first author on this research study: “So far, we didn’t know that microdeletions, loss of entire chromosomal segments including several genes, can also be a cause for common diseases. This finding will help understand why people suffer from common disorders including epilepsies.”

Up to three percent of the population experience epileptic seizures and one percent suffers from epilepsy, which is characterised by recurrent seizures. The researchers hope that understanding how this genetic defect leads to epilepsy will help develop new drugs against seizures. So far, most genes for epilepsy were only found in rare form of epilepsies. However, hereditary factors are long known to play a much larger role, contributing to many common forms of seizure disorders. Hence, the discovery of the 15q13.3 microdeletions in common epilepsies is an important milestone.

44 coauthors contributed to the recent study, which was coordinated by Dr. Thomas Sander from the Cologne Center of Genomic at the University of Cologne, Germany. On a European level, this project included German groups from Berlin, Bonn, Marburg, Ulm as well as groups from Vienna, Copenhagen, Utrecht (NL), Geneva, Troina (Italy), Marseille and Nice. The research study was performed in collaboration with the group of Dr. Evan Eichler at the Department of Genome Sciences and Howard Hughes Medical Institute at the University of Washington, Seattle. Dr. Eichler is one of the pioneers of research on microdeletions in human disease.

Many authors on this research papers are part of the European EPICURE project of the European Union, a large consortium dedicated to the research of epilepsies.