Last modified: 2018-09-09
Abstract
Introduction To summarize the clinical features of epilepsy associated with TBC1D24 mutations.
Methods The epilepsy patients with TBC1D24 compound heterozygous mutations were collected. TBC1D24 mutations were identified by next-generation sequencing panels of epilepsy or whole exome sequencing.
Results 19 epilepsy patients with TBC1D24 compound heterozygous mutations were enrolled. The onset age of seizure ranged from one day to eight months. Focal myoclonus was presented in 18 patients, which was migrating and alternating, lasting a few minutes to several days, and could be terminated by sleep or sedation drugs. Myoclonus could be triggered by fever or infections in 12 (63%, 12/19) patients. Generalized tonic-clonic seizures were occurred in four (21%, 4/19) patients. Developmental delay was presented in 12 patients (58%, 12/19). Four patients exhibited hearing loss. Brain magnetic resonance imaging were abnormal in 8 patients (42%, 8/19), including cerebellar and/or cerebral atrophy with cerebellar abnormal signals, and corpus callosum dysplasia. 11 patients were captured with focal myoclonus by video electroencephalogram, but 10 without correlated epileptiform discharges. Four patients were diagnosed with epilepsy of infancy with migrating focal seizures, two with progressive myoclonic epilepsies, one with Dravet syndrome, and five with unclassified epileptic encephalopathy.
Conclusion The clinical phenotypes of epilepsy with TBC1D24 mutation were heterogeneous. Prolonged multifocal myoclonus was common feature of this disease. Focal myoclonus could be triggered by fever or infection and terminated by sleep or sedation drugs. Most patients presented developmental delay. The neuroimaging feature of TBC1D24 related epilepsy patients was cerebellar atrophy with abnormal signals.