A deletion on chromosome 15 is the most prevalent risk factor for common epilepsies identified to date, according to a study published online in Nature Genetics.
Up to one-third of all epilepsies are termed idiopathic generalized epilepsies (IGE), for which genetic causes are largely unknown. Previous work has mapped potential genetic risk factors to a region on chromosome 15, which has recently been linked to elevated risk for different combinations of mental retardation, schizophrenia, autism and epilepsy.
Thomas Sander and a consortium of investigators report that this deletion is present in approximately 1% of individuals with IGE who do not have mental retardation or psychosis. This result suggests that the chromosome 15 deletion can give rise to a wide range of neurological disorders, with IGE being the most common outcome. The deletion harbors at least seven genes, one of which is CHRNA7, which regulates signaling at neuronal synapses. Mutations in other members of this gene family are known to cause a rare form of epilepsy, suggesting that deletion of CHRNA7 may underlie the chromosome 15 association with IGE.
Thomas Sander (University of Cologne, Germany)
Abstract available online.
(C) Nature Genetics press release.
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