A hereditary condition, caused by a defect (a deletion) in chromosome 7, marked by a characteristic ‘elfin’ facial appearance (including large eyes, a wide mouth, and small chin), hypercalcaemia, short stature, mental retardation, and aortic stenosis. Most affected children are highly sociable and have unusual conversational ability, using a rich and complex vocabulary. The condition can be diagnosed prenatally. J. C. P. Williams (20th century), British physician
Subjects: Psychology — Medicine and Health.