Epilepsja związana z wariantami genu SYNGAP1: cechy kliniczne sześciu przypadków i przegląd piśmiennictwa

OBJECTIVE: To summarize the clinical characteristics, treatment response, and prognosis of epilepsy associated with gene variants. METHODS: Clinical and genetic data of six children diagnosed with SYNGAP1-related epilepsy at the Children's Hospital Affiliated to Zhengzhou University between November 2019 and February 2025 were retrospectively analyzed. RESULTS: Among the six patients (four males and two females), the median age at seizure onset was 2 years and 8 months. All patients showed moderate to severe motor and language developmental delay, with prominent language impairment. Seizure types were heterogeneous, mainly including myoclonic seizures, eyelid myoclonia with or without absence seizures, myoclonic-atonic seizures, and absence seizure. Two patients had a history of febrile seizures, and four had identifiable seizure triggers. Electroencephalography revealed generalized or multifocal epileptiform discharges in all patients. Genetic analysis revealed that all six variants were , involving five distinct variant sites, three of which were previously unreported. Variant types included three nonsense mutations, two frameshift mutations, and one missense mutation. Five of the six patients achieved seizure control or marked seizure reduction with valproate treatment, but seizures tended to recur after drug withdrawal. Among them, three patients achieved seizure freedom after combination therapy with levetiracetam, and two patients with drug-resistant epilepsy achieved seizure control after the addition of clobazam. CONCLUSIONS: Myoclonic seizures, absence seizures, and eyelid myoclonia are common in -related epilepsy. Valproate is generally effective, but combination therapy is often required. Neurodevelopmental impairment shows limited improvement despite seizure control.