Hyperekplexia: A forgotten diagnosis clinched by next-generation sequencing

Hyperekplexia is a rare early neonatal onset, potentially treatable, neurological disorder, characterized by a triad of immediate neonatal-onset stiffness, an exaggerated startle reflex in response to tactile or auditory stimuli followed by short periodical generalized stiffness. It is a monogenic genetically heterogeneous condition which can be potentially life threatening due to apneic episodes and is usually misdiagnosed as seizures. Here, we report two female siblings with hyperekplexia who were being treated by multiple antiepileptic medications for seizure-like episodes. Hyperekplexia was diagnosed by next-generation sequencing, which has emerged as a powerful diagnostic tool over the last few years.