The comparison of nine examples of trisomy for the distal segment of 11q permits definition of a clinical syndrome which includes the following: axial hypotonia with hypertonia of the limbs; an old-looking wrinkled face; a large beaked nose; microretrognathia with malformation of the palate; low-set ears; a prominent anterior helix; a prominent anthelix; a short neck; a narrow chest with nipples set widely apart; micropenis in the boys; congenital heart disease; renal agenesis or malformations of the urinary tract; agenesis of the thoracic girdle; dysplasia of the acetabulum; clubfeet.