Stereotyped Upper Limb Movement in MECP2 Duplication Syndrome.

A 23-year-old man had epilepsy, mental retardation, and a stereotyped movement (figure 1 and video1), which was exacerbated by emotion. No abnormality was detected in the EEG during this movement. Array comparative genomic hybridization showed a Xq28 duplication: arr[GRCh37]Xq28(153032004_153406233)x2 (figure 2).