AUTHOR=Zeng Qi , Yang Ying , Duan Jing , Niu Xueyang , Chen Yi , Wang Dan , Zhang Jing , Chen Jiaoyang , Yang Xiaoling , Li Jinliang , Yang Zhixian , Jiang Yuwu , Liao Jianxiang , Zhang Yuehua 

TITLE=SCN2A-Related Epilepsy: The Phenotypic Spectrum, Treatment and Prognosis

JOURNAL=Frontiers in Molecular Neuroscience

VOLUME=Volume 15 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/molecular-neuroscience/articles/10.3389/fnmol.2022.809951

DOI=10.3389/fnmol.2022.809951

ISSN=1662-5099

ABSTRACT=Objective: The aim of this study was to analyze the phenotypic spectrum, treatment and prognosis of 72 Chinese children with SCN2A variants. 
Methods: The SCN2A variants were detected by next-generation sequencing. All patients were followed up at a pediatric neurology clinic in our hospital or by telephone.
Results: In 72 patients with SCN2A variants, the seizure onset age ranged from the first day of life to 2 years and 6 months.  The epilepsy phenotypes included febrile seizures (plus)(n=2), benign (familial) infantile epilepsy(n=9), benign familial neonatal-infantile epilepsy(n=3), benign neonatal epilepsy(n=1), West syndrome(n=16), Ohtahara syndrome(n=15), epilepsy of infancy with migrating focal seizures (n=2), Dravet syndrome (n=1), early infantile epileptic encephalopathy (n=15), and unclassifiable developmental and epileptic encephalopathy (n=8). 79.1% (57/72) patients had varying degrees of developmental delay. All patients had abnormal MRI findings with developmental delay. 91.6% (55/60) patients with de novo SCN2A variants had development delay, while only 16.7% (2/12) patients with inherited SCN2A variants had abnormal development. 83.9% (26/31) SCN2A variants that were located in transmembrane regions of the protein were detected in patients with development delay. 69.2% (9/13) SCN2A variants detected in patients with normal development were located in the non-transmembrane regions. 54.2%（39/72）patients were seizure-free at a median age of 8 months. Oxcarbazepine has been used by 38 patients, and seizure-free was observed in 11 of them (11/38, 28.9%), while 6 patients had seizure worsening by oxcarbazepine. All 3 patients used oxcarbazepine and with seizure onset age ＞1 year presented seizure exacerbation after taking oxcarbazepine. Valproate has been used by 53 patients, seizure-free was observed in 22.6% (12/53) of them.