Targeted next-generation sequencing (NGS) was performed for 120 patients with unexplained epilepsy, including 71 patients with early-onset epileptic encephalopathies, and 16 patients with Dravet syndrome (including three patients with a Dravet-like phenotype) but without SCN1A pathogenic variants.
Pathogenic significance of SCN1A splicing variants causing Dravet syndrome: Improving diagnosis with targeted sequencing for variants by in silico analysis.
We investigated how two distinct mutations in SCN1A differentially affect electrophysiological properties of the patient-derived GABAergic neurons and clinical severities in two Dravet syndrome (DS) patients.
This study expanded the mutational spectrum for the SCN1A gene, and also provided clinical and genetic evidence for the hypothesis that genetic modifiers may contribute to the variable manifestation of Dravet syndrome patients with SCN1A mutations.
The most important determinant of disease severity is the type of variant, with variants that cause a complete loss of function of the SCN1A protein (α-subunit of the neuronal sodium channel Nav1.1) being detected almost exclusively in Dravet syndrome patients.
As an in vitro model of this disease, we previously generated an induced pluripotent stem cell (iPSC) line from a patient with DS carrying a c.4933C>T (p.R1645*) substitution in SCN1A.
Furthermore, we identified age at first afebrile seizure as an important predictor for evolution of seizures into Dravet syndrome and for the severity of Dravet syndrome, which can be used to counsel parents of young patients with SCN1A-related seizures.
We describe two females who fulfill the diagnostic criteria for classic RTT, with pathogenic de novo mutations in SCN1A, which usually leads to Dravet syndrome.
Thus, the high risk of SUDEP in DS may result from a predisposition to cardiac arrhythmias in addition to seizures, reflecting expression of SCN1A in heart and brain.
Rare variants of small effect size in neuronal excitability genes influence clinical outcome in Japanese cases of SCN1A truncation-positive Dravet syndrome.
We used an ultra-sensitive quantification method, micro-droplet digital PCR (mDDPCR), to detect parental mosaicism of the proband's pathogenic mutation in SCN1A, the causal gene of DS in 112 families.
We describe a distinctive speech, language, and oral motor phenotype in children and adults with DS associated with mutations in <i>SCN1A.</i> Recognizing this phenotype will guide therapeutic intervention in patients with DS.
Zebrafish with a mutation in the SCN1A homologue recapitulate spontaneous seizure activity and mimic the convulsive behavioural movements observed in Dravet syndrome.
Mutations in the voltage-gated sodium channel (VGSC) gene SCN1A, encoding the Na<sub>v</sub>1.1 channel, are responsible for a number of epilepsy disorders including genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (DS).