Axenfeld-Rieger syndrome (ARS) is a generic term used to designate overlapping genetic disorders, in which the major physical condition is anterior segment dysgenesis of the eye. Patients with ARS may also present with multiple variable congenital anomalies.

An abnormal configuration of the lower lip such that it is turned outward i.e., everted, with the Inner aspect of the lower lip vermilion (normally opposing the teeth) being visible in a frontal view.