Ablepharon-macrostomia syndrome (AMS) is a congenital ectodermal dysplasia characterized by absent eyelids, macrostomia, microtia, redundant skin, sparse hair, dysmorphic nose and ears, variable abnormalities of the nipples, genitalia, fingers, and hands, largely normal intellectual and motor development, and poor growth (summary by Marchegiani et al., 2015).

Most patients with craniofacial microsomia-2 (CFM2) exhibit isolated unilateral or bilateral grade III microtia, with or without aural atresia, although some patients exhibit only minor external ear defects. Mandibular hypoplasia, micrognathia, and dental anomalies have also been observed (Quiat et al., 2023; Mao et al., 2023). For a general phenotypic description and discussion of genetic heterogeneity of craniofacial microsomia, see CFM1 (164210).