Proximal Xq28 duplication syndrome

A rare X-linked genomic disorder associated with interstitial chromosomal duplications at Xq28 encompassing the <i>MECP2</i> gene. It is characterized in males by infantile onset hypotonia, severe global developmental delay, intellectual disability, progressive spasticity, seizures, gastrointestinal symptoms and recurrent respiratory infections. In females, the phenotype is more variable.