A rare chromosomal anomaly syndrome resulting from the partial duplication of the long arm of chromosome 22 with a highly variable phenotype. Principle characteristics are developmental delay, intellectual disability, hypotonia, growth retardation, velopharyngeal insufficiency, mild craniofacial dysmorphism (microcephaly, tall/broad forehead, small downslanting palpebral fissures, hooded eyelids, flat nasal bridge, low posterior hairline) and digital anomalies. Congenital heart malformations, visual and hearing impairment, urogenital abnormalities and seizures have also been reported. [from
SNOMEDCT_US]