Hyperekplexia, also known as startle disease, is a paroxysmal neurological disorder caused by defects in glycinergic neurotransmission. Hyperekplexia is characterized by neonatal hypertonia and an exaggerated startle reflex in response to acoustic or tactile stimuli. Genetic analysis has revealed mutations in genes for several postsynaptic proteins involved in orchestrating glycinergic neurotransmission, including the glycine receptor (GlyR) alpha1 and beta subunits.
