STXBP1 Encephalopathy: Cannabidiol as a Treatment Option and Expansion of the Genotype-Phenotype Spectrum - Case...

STXBP1 encodes syntaxin-binding protein 1, a protein with a role in trafficking of syntaxin-1 to the synapse and synaptic neurotransmitter release. Mutations in STXBP1 are associated with a wide range of neurodevelopmental phenotypes, including epilepsy, intellectual disability, and movement disorders.

We report 4 individuals with pathogenic variants in STXBP1, including 2 previously unreported variants, presenting with a range of severity. One severely affected child with refractory seizures and distressing dystonia responded well to treatment with cannabidiol (CBD), with both seizure cessation and improvement in tone.

STXBP1 variants are associated with significant phenotypic pleiotropy and a wide spectrum of severity. CBD may be beneficial for severely affected individuals with seizures and movement disorders that are refractory to conventional treatments.