Drop episodes in Coffin-Lowry syndrome: exaggerated startle responses treated with clonazepam.

A 16-year-old girl had fully manifested Coffin-Lowry syndrome and drop episodes. Her drop episodes were precipitated by sudden unexpected tactile or auditory stimuli associated with the electrostatic circumstances in her leg muscles immediately after the stimuli. Studies revealed that her drop episode symptom was an unusual type of startle response and that it may be associated with Coffin-Lowry syndrome.