Brief CommunicationHyperactive behavior in a family with autosomal dominant lateral temporal lobe epilepsy caused by a mutation in the LGI1/epitempin gene

- A heterozygous c.431+1G>A substitution in LGI1 was detected in all patients.
- A common founder mutation with a French family was ruled out.
- ADHD symptoms were scored in all family members.
- Significantly more hyperactivity symptoms were found in LGI1 mutation carriers.

Autosomal dominant lateral temporal lobe epilepsy (ADLTE) is characterized by focal seizures with auditory features or aphasia. Mutations in the leucine-rich glioma-inactivated 1 (LGI1) gene have been reported in up to 50% of families with ADLTE. Attention-deficit/hyperactivity disorder (ADHD) symptoms have not yet been reported in these families. Clinical data were collected from a family with five affected members. Leucine-rich glioma-inactivated 1 exons and boundaries were sequenced by standard methods. Attention-deficit/hyperactivity disorder symptoms were scored based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. Affected members had seizures with auditory features and psychic auras, and some experienced nightmares. A heterozygous c.431+1G>A substitution in LGI1 was detected in all members. Significantly more hyperactivity symptoms were found in family members carrying the LGI1 mutation. This study expands the phenotypic spectrum associated with ADLTE due to LGI1 mutation and underlines the need for more systematic evaluation of ADHD and related symptoms.