Susceptibility to Juvenile Myoclonic Epilepsy Associated with the EFHC1 Gene: First Case Report in Turkey

Juvenile myoclonic epilepsy (JME), characterized by predominating myoclonic seizures, is one of the most common forms of generic generalized epilepsy. Generic studies in JME reported susceptibility associated with EFHC1 gene. A 26-year-old male patient was admitted to our epilepsy outpatient clinic unit with one generalized tonic-clonic seizure and with previous myoclonic seizures started at the age of 17 years described as jerky movements. His neurologic examination and neuroimaging studies were normal. The family history was unremarkable. His electroencephalography was recorded under treatment and showed short-lasting paroxysms consisting of 6-7 Hz generalized slow waves and superimposed sharp contoured waves, slightly prominent over the posterior halves of the hemispheres, interpreted as generalized paroxysmal abnormality. After performing whole exom sequencing and investigating epilepsy-related genes, a heterozygous missense variant was found in EFHC1 gene causing amino acid change [rs137852776: NM_018100.4: c.685T>C;p 15 (Phe229Leu)]. His seizures are still under control with valproate 1000 mg/d. Variants in EFHC1 gene are the most commonly observed genetic abnormalities in patients with familial JME in different countries. Our study reported a EFHC1 gene variation in a patient typical JME for the first time in our country. Our finding is important for future clinical studies and genetic counseling in JME.