Angelman syndrome

Maternal chromosome at 15q11

Seizures, puppet-like ataxia, frequent laughter, hand flapping, severe intellectual disability

DiGeorge syndrome (DiGeorge anomaly, velocardiofacial syndrome, pharyngeal pouch syndrome, thymic aplasia)

22q11.21

Hypoplasia or lack of thymus and parathyroids, cardiac anomalies, cleft palate, intellectual disability, psychiatric problems

Langer-Giedion syndrome (trichorhinophalangeal syndrome type II)

8q24.1

Exostosis, cone epiphyses, sparse hair, bulbous nose, hearing loss, intellectual disability

Miller-Dieker syndrome

17p13.3

Lissencephaly; short, upturned nose; severe growth retardation; seizures; severe intellectual disability

Prader-Willi syndrome

Paternal chromosome at 15q11

In infancy: Hypotonia, poor feeding, failure to thrive

In childhood and adolescence: Obesity, hypogonadism, small hands and feet, intellectual disability, obsessive-compulsive behaviors

Rubinstein-Taybi syndrome

16p13−

Broad thumbs and large toes, prominent nose and columella, intellectual disability

Smith-Magenis syndrome

17p11.2

Brachycephaly, midfacial hypoplasia, prognathism, hoarse voice, short stature, intellectual disability

Williams syndrome

7q11.23

Aortic stenosis, intellectual disability, elfin facies, transient hypercalcemia in infants