Abstracts

Rationale: Eyelid Myoclonia with Absences (EMA) is an uncommon absence epilepsy syndrome that is often refractory to treatment. The clinical genetics of EMA has not been well characterized although a family history of seizures is not infrequent. Methods: Individuals with EMA were ascertained by referral and through the investigators' clinical practices. All available family members were assessed for seizures using a validated seizure questionnaire. Electroclinical data were obtained on each proband and all affected family members; pedigrees were constructed. Families were analyzed for phenotypic patterns. Results: Eighteen individuals with EMA were recruited. A history of seizures was found in 34 relatives in 15/18 (83%) families. In terms of epilepsy syndromes, nine relatives from 7/15 families had febrile seizures. Two relatives had EMA. Classical Genetic Generalized Epilepsy (GGE) syndromes were seen in five relatives: two Generalized Tonic-Clonic Seizures alone, two Childhood Absence Epilepsy (CAE) and one Juvenile Myoclonic Epilepsy. Genetic Epilepsy with Febrile Seizures Plus (GEFS+) phenotypes occurred in 16 relatives. On review of the epilepsy syndromes within each family, seven families had a pattern consistent with GEFS+ while three families had classical GGE. Conclusions: The clinical genetics of EMA is suggestive of complex inheritance with shared genetic determinants overlapping with both classical GGE and GEFS+. The epilepsy syndromes in relatives of probands with EMA differ from those found in families of probands with CAE supporting the concept that EMA is a distinct syndrome from CAE. This presumably reflects different genetic components contributing to their genetic architecture.