<unk>  (; "exaggerated surprise") is a very rare neurologic disorder classically characterised by pronounced startle responses to tactile or acoustic stimuli and hypertonia. The hypertonia may be predominantly truncal, attenuated during sleep and less prominent after a year of age. Classic<unk>  is caused by genetic mutations in a number of different genes, all of which play an important role in glycine neurotransmission. Glycine is used by the central nervous system as an inhibitory neurotransmitter.<unk>  is generally classified as a genetic disease, but some disorders can mimic the exaggerated startle of<unk> .
Hyperekplexia
Cynanthropy
Metamorphopsia
Dysmorphopsia
Misophonia
Polycoria
Agraphesthesia
Xanthopsia