A rare chromosomal anomaly syndrome resulting from the partial duplication of the long arm of chromosome 11 with high phenotypic variability. Principle characteristics are craniofacial dysmorphism (brachycephaly/plagiocephaly, low-set, posteriorly rotated ears, short philtrum, micrognathia) and intellectual disability. Short stature and seizures, as well as cardiac (atrial septal defect), skeletal (brachy/syndactyly) and genital (micropenis, cryptorchidism) abnormalities may also be associated. Neurodevelopmental anomalies (pain insensitivity, sensorineural hearing loss, expressive language deficiency) and neuropsychiatric disorders (autistic features, auditory hallucination, self-talking) have also been reported. [from SNOMEDCT_US]