Gene Found for Common Form of Epilepsy

A gene mutation linked to the most common form of epilepsy has been found that could in the future lead to a genetic test for the condition.

The use of exome sequencing detected the gene for autosomal dominant familial focal epilepsy with variable foci (FFEVF) which is notable because family members have seizures originating from different cortical regions.

A team of scientists working with those at University of South Australia (Adelaide, SA, Australia) studied about 90 families where two members had epilepsy. The exomes of individuals were independently sequenced both in Australia and in The Netherlands. The coding sequences were enriched using the SureSelect Human All Exon 50Mb kit (Agilent Technologies; Santa Clara, CA, USA). After sequence capture and amplification, fragments were sequenced using a SOLiD v4 instrument (Applied Biosystems; Mulgrave, VIC, Australia).

The results showed that a gene called DEP domain-containing 5 (DEPDC5) causes focal epilepsy in about 12% of families in which only two people have focal epilepsy. This high frequency establishes DEPDC5 mutations as a common cause of familial focal epilepsies. As well as opening new opportunities for diagnosing epilepsy, the scientists believe their discovery will also lead to better targeted treatments.

The identification of DEPDC5 as the gene underlying FFEVF substantially advances understanding of the pathogenesis of epilepsy by implicating another new gene pathway. Apart from enabling the diagnosis of FFEVF through molecular testing, these findings also enable strategies to be devised to improve prognosis through tailored treatment targeting DEPDC5.

Ingrid E. Scheffer, MD, professor and pediatric neurologist, of the Florey Neuroscience Institute (Melbourne, VIC, Australia) said, "This discovery is paradigm shifting, if you have focal epilepsy and there is no cause known, then this gene should be tested to look for a mutation." The study was published on March 31, 2013, in the journal Nature Genetics.

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University of South Australia
Agilent Technologies
Applied Biosystems