Description:
<jats:p>Autosomal dominant sleep-related hypermotor epilepsy is a rare disease caused by pathogenic variants of <jats:italic toggle="yes">CHRNB2, CHRNA4</jats:italic>, and <jats:italic toggle="yes">CHRNA2</jats:italic> genes, with nocturnal frontal lobe epilepsy as the main symptoms. Syntaxin binding protein 1 (<jats:italic toggle="yes">STXBP1</jats:italic>) gene mutation can cause developmental and epileptic encephalopathy 4, mainly presenting as a developmental and epileptic encephalopathy. We performed the exome-targeted next-generation sequencing in our patient and identified two heterozygous variants: c.963 + 2T>C of <jats:italic toggle="yes">STXBP1</jats:italic> and c.520_527delinsTGCTAC (p.R174Cfs*16) of <jats:italic toggle="yes">CHRNB2</jats:italic>. Molecular analysis was performed of the variant c.963 + 2T>C. Aberrantly spliced products were observed, proving the pathogenicity of this variant. Refractory seizures and developmental delay could be explained. Although the variant c.520_527delinsTGCTAC could cause the truncation of the proteins, it was ultimately determined to be nonpathogenic. The startle-like responses that occurred occasionally during the night were ultimately determined to be an uncommon phenotype caused by the <jats:italic toggle="yes">STXBP1</jats:italic> variant.</jats:p>