Dravet Syndrome Associated With a CSNK2B-Related Neurodevelopmental Disorder.

Dravet syndrome (DS) is a developmental epileptic encephalopathy characterized by prolonged febrile and afebrile focal clonic as well as generalized seizures. The most common genetic etiology is SCN1A, but other genetic disorders can present with the phenotype. A two-year-and-11-month-old Caucasian female patient of Russian descent, with a history of developmental delay and recurrent prolonged febrile focal clonic seizures since the age of 2-3 months, presented with afebrile status epilepticus. Genetic testing identified a de novo mutation in CSNK2B. Her clinical history and semiology were consistent with DS. The CSNK2B mutation is associated with neurodevelopmental disorders characterized by developmental delays and epilepsy of varying severity. This is the first reported case of a child with a CSNK2B mutation presenting with a DS phenotype. The pathophysiological mechanisms of CSNK2B mutations involve disrupted casein kinase 2 (CK2) activity, which impacts synaptic plasticity and shares similarities with the synaptic dysfunction seen in other genes associated with the DS phenotype. Identifying such cases expands the knowledge base and understanding of the genetic landscape of DS.