Mutations in LGI1 have been reported in several families with autosomal dominant lateral temporal epilepsy. In a family in which three patients also experienced migraine-like episodes we found a novel three base-pair deletion (c.377_379delACA), resulting in the deletion of an asparagine residue in the second leucine-rich repeat. Functional studies showed that the mutated protein was not secreted when transfected in COS cells, consistent with a causative role in the disease.