SCN1A-Related Epilepsy: Novel Mutations and Rare Phenotypes

Rui Ma; Yiran Duan; Liping Zhang; Xiaohong Qi; Lu Zhang; Sipei Pan; Lehong Gao; Chaodong Wang; Yuping Wang

doi:10.3389/fnmol.2022.826183

SCN1A-Related Epilepsy: Novel Mutations and Rare Phenotypes

Front Mol Neurosci. 2022 May 19:15:826183. doi: 10.3389/fnmol.2022.826183. eCollection 2022.

Authors

Rui Ma^{1

2}, Yiran Duan^{1

2}, Liping Zhang³, Xiaohong Qi³, Lu Zhang^{1

2}, Sipei Pan^{1

2}, Lehong Gao^{1

2}, Chaodong Wang¹, Yuping Wang^{1

2}

Affiliations

¹ Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China.
² Beijing Key Laboratory of Neuromodulation, Beijing, China.
³ Department of Pediatrics, Xuanwu Hospital, Capital Medical University, Beijing, China.

Abstract

Objectives: To expand the genotypes and phenotypes of sodium voltage-gated channel alpha subunit 1 (SCN1A)-related epilepsy.

Methods: We retrospectively collected the clinical and genetic information of 22 epilepsy patients (10 males, 12 females; mean: 9.2 ± 3.9 years; 3.9-20.3 years) carrying 22 variants of SCN1A. SCN1A mutations were identified by next-generation sequencing.

Results: Twenty-two variants were identified, among which 12 have not yet been reported. The median age at seizure onset was 6 months. Sixteen patients were diagnosed with Dravet syndrome (DS), two with genetic epilepsy with febrile seizures plus [one evolved into benign epilepsy with centrotemporal spikes (BECTS)], one with focal epilepsy, one with atypical childhood epilepsy with centrotemporal spikes (ABECTS) and two with unclassified epilepsy. Fourteen patients showed a global developmental delay/intellectual disability (GDD/ID). Slow background activities were observed in one patient and epileptiform discharges were observed in 11 patients during the interictal phase.

Significance: This study enriches the genotypes and phenotypes of SCN1A-related epilepsy. The clinical characteristics of patients with 12 previously unreported variants were described.

Keywords: BECTS; SCN1A gene; cohort; epilepsy; novel mutation.