A rare sex chromosome number anomaly disorder characterized, genetically, by the presence of an extra X and Y chromosome in males and, clinically, by tall stature, dysfunctional testes associated with infertility and insufficient testosterone production, cognitive, affective and social functioning impairments, global developmental delay, and an increased risk of congenital malformations.

Increased thickness of the lower lip, leading to a prominent appearance of the lower lip. The height of the vermilion of the lower lip in the midline is more than 2 SD above the mean. Alternatively, an apparently increased height of the vermilion of the lower lip in the frontal view (subjective).