Phenotypic spectrum of nervous system diseases in children associated with KCNMA1 gene mutations

Objective To summarize the clinical phenotypes and genetic mutations of children with KCNMA1 gene mutations. Methods A retrospective analysis was performed for the clinical data of ten children with heterozygous KCNMA1 gene mutations who attended Pediatric Medical Center of Peking University First Hospital from March 2013 to May 2023, and their cli-nical manifestations, cranial radiological features, and electroencephalogram (EEG) features were summarized. Results Among the ten children with KCNMA1 mutations, there were eight boys and two girls. Nine different KCNMA1 gene mutations were identified, including five missense mutations, three frame-shifting mutations, and one splice site mutation, among which there were seven de novo mutations and two inheritable mutations. Among the ten children with KCNMA1 mutation, six presented with seizures alone, three presented with seizures and paroxysmal movement disorders, and one presented with paroxysmal movement disorders alone. For the nine children with seizures, t