Levodopa responsive Parkinsonism in adults with Angelman Syndrome.

Two intellectually disabled adults with Angelman Syndrome are reported who developed intermittent episodes of a severe resting tremor, cogwheel rigidity and bradykinesia in their late teens. The Parkinsonism was not due to medications and there was a dramatic improvement with levodopa therapy. The association between Angelman Syndrome and Parkinsonism has not previously been described.