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jws-mds.21277.mpg13503KSegment 1. Patient at age 5 weeks. An acute episode of horizontal nystagmus during eating.Segment 2. Patient at age 4 months. There are two episodes of tonic upward gaze accompanied by tonic contraction of different muscle groups of the face and limbs.Segment 3. Patient at age 10 months. There is an episode of intermittent upward gaze accompanied by involuntary choreiform movements of face and limbs; note dysmorphic features, severe axial hypotonia, and absence of psychomotor development.

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