KCNQ2 Gain-of-Function Mutation Presenting as Respiratory Dysfunction and Non-epileptic Myoclonus.

Epileptic encephalopathies are characterized by altered mental status, primarily driven by aggressive and abnormal epileptiform activities in the brain. These conditions often present with intractable seizures associated with progressive neurocognitive decline or stagnation. Mutations in the KCNQ2 gene represent one of the most common genetic causes of neonatal epileptic encephalopathies. This case report describes a rare presentation of a KCNQ2 gain-of-function mutation associated with respiratory dysfunction and non-epileptic myoclonus. This case report describes a rare presentation of a KCNQ2 gain-of-function mutation associated with respiratory dysfunction and non-epileptic myoclonus, with the patient exhibiting an uncommon phenotype of central hypopnea and non-epileptic, stimulus-sensitive myoclonus.