Genotypes and clinical features of neonatal-onset genetic epilepsy in 141 patients

Abstract

Objective: To summarize the genotypes and clinical features of neonatal-onset genetic epilepsy. Methods: Patients (114 cases) with identified gene variants were collected from May 2013 to May 2019 in Peking University First Hospital, retrospectively. The genotype, clinical, electroencephalographic and neuroimaging characteristics were analyzed. Results: A total of 141 neonatal-onset epilepsy patients with identified gene variants were enrolled, including 76 males and 65 females and involving 33 epilepsy genes. Top five genes were KCNQ2 (56 cases), SCN2A (25 cases), STXBP1 (9 cases), CDKL5 (8 cases) and KCNT1 (6 cases), accounting for 73.8% (104/141). The age of seizure onset was 3(1-28) days of age, 71.6% (101/141) were within 1 week of age. The age of genetic diagnosis was 4 months (1 month to 13 years) of age. A total of 130 patients presented focal seizures; 47 patients presented epileptic spasms. Other seizure types included generalized tonic-clonic seizures, clonic seizures, myoclonic seizures, tonic seizures and absence seizures. Fifty-eight patients experienced multiple seizure types. The results of video-electroencephlogram (VEEG) were abnormal in 127 patients and in 62 patients clinical seizures were captured. Global developmental delay was presented in 122 patients. Epilepsy syndromes were diagnosed in 59 patients. Thirteen patients were diagnosed as Ohtahara syndrome (OS), 9 as epilepsy of infancy with migrating focal seizures (EIMFS), 17 as West syndrome (WS), 4 as OS developed to WS, 9 as benign neonatal epilepsy (BNE), 2 as benign familiar neonatal-infantile epilepsy (BFNIE), 2 as benign infantile epilepsy (BIE) and 3 as benign familial infantile epilepsy (BFIE). Sixty-seven patients were diagnosed as unclassified early infantile epileptic encephalopathy (EIEE), 13 patients could not be diagnosed as any epilepsy syndrome, and 2 patients were diagnosed as pyridoxine-dependent epilepsy. Forty-six patients had abnormal neuroimaging including cortical atrophy, corpus callosum dysplasia and cerebellar atrophy, involving 19 genes. Conclusions: Neonatal-onset epilepsy is related to many different genes. Seizure onset age of most patients is within one week after birth. Focal seizures and epileptic spasms are more common. Some patients show abnormal neuroimaging.