Constriction rings syndrome is a congenital limb malformation disorder with an extremely variable clinical presentation characterized by the presence of partial to complete, congenital, fibrous, circumferential, constriction bands/rings on any part of the body, although a particular predilection for the upper or lower extremities is seen. Phenotypes range from only a mild skin indentation to complete amputation of parts of the fetus (e.g. digits, distal limb). Compression from the rings may lead to edema, skeletal anomalies (e.g. fractures, foot deformities) and, infrequently, neural compromise.

A condition in which middle parts of the foot (toes and metatarsals) are missing giving a cleft appearance. The severity is very variable ranging from slightly hypoplastic 3rd toe over absent 2nd or 3rd toes as far as oligo- or monodactyl feet.