To test this hypothesis, we subjected 21-23-day-old mice expressing the human SCN1A GEFS+ mutation R1648H to prolonged hyperthermia, and then examined seizure and behavioral phenotypes during adulthood.
We screened for PCDH19 mutations in 75 girls diagnosed with Dravet syndrome (DS) without a SCN1A mutation and 29 girls with fever-sensitive and cluster seizures.
Our findings broaden the clinical spectrum of SCN2A mutations, which resembles clinical phenotypes of SCN1A mutations by manifesting as fever sensitive seizures, and highlights that SCN2A mutations are an important cause of early-onset epileptic encephalopathies with movement disorders.
Therefore, we performed a genome-wide screening for copy number variations (CNVs) in 36 patients with SCN1A-negative fever-associated syndromic epilepsies.
The early clinical features of DS patients with SCN1A mutations were reviewed with attention to the seizures induced by fever and other precipitating factors before the first year of life.
The three criteria that best predicted a mutation in SCN1A included exacerbation with hyperthermia, normal development before seizure onset, and the appearance of ataxia, pyramidal signs, or interictal myoclonus.
Complete loss of function in the Na(v) 1.1 channel encoded by the SCN1A gene is associated with severe myoclonic epilepsy in infancy (SMEI), a devastating infantile-onset epilepsy with ataxia, cognitive dysfunction, and febrile and afebrile seizures resistant to current medications.
The aim of this study was to determine the genetic defect in a 4-generational family with an epileptic disorder characterized by febrile and afebrile polymorphic seizures and mild to severe mental retardation by means of analyzing the neuronal voltage-gated sodium channel alpha-subunit gene SCN1A for mutations.
Intrafamilial variability in phenotype severity indicates that SCN1A loss of function causes a phenotypic spectrum in which seizures precipitated by fever are prominent and schematic syndrome subdivisions would be inappropriate.
Patients with PCDH19 and SCN1A mutations had very similar clinical features including the association of early febrile and afebrile seizures, seizures occurring in clusters, developmental and language delays, behavioural disturbances, and cognitive regression.
We performed mutation analyses of the sodium-channel gene SCN1A in two Japanese brothers with clinical features of SMEI and their parents, who had no history of febrile and epileptic seizures.