Coffin-Lowry syndrome (CLS) is a rare genetic neurological disorder characterized by psychomotor and growth retardation, facial dysmorphism, digit abnormalities, and progressive skeletal changes.

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).