| A rare chromosomal anomaly syndrome, resulting from the partial duplication of the long arm of chromosome 22, with a highly variable phenotype principally characterized by developmental delay, intellectual disability, behavioral anomalies, and non-specific craniofacial dysmorphism. Congenital heart malformations, visual and hearing impairment, urogenital abnormalities, and seizures have also been reported. Penetrance is incomplete. In 70% of cases, the duplication is inherited from an asymptomatic parent. |
