Short-rib thoracic dysplasia (SRTD) with or without polydactyly refers to a group of autosomal recessive skeletal ciliopathies that are characterized by a constricted thoracic cage, short ribs, shortened tubular bones, and a 'trident' appearance of the acetabular roof. SRTD encompasses Ellis-van Creveld syndrome (EVC) and the disorders previously designated as Jeune syndrome or asphyxiating thoracic dystrophy (ATD), short rib-polydactyly syndrome (SRPS), and Mainzer-Saldino syndrome (MZSDS). Polydactyly is variably present, and there is phenotypic overlap in the various forms of SRTDs, which differ by visceral malformation and metaphyseal appearance. Nonskeletal involvement can include cleft lip/palate as well as anomalies of major organs such as the brain, eye, heart, kidneys, liver, pancreas, intestines, and genitalia. Some forms of SRTD are lethal in the neonatal period due to respiratory insufficiency secondary to a severely restricted thoracic cage, whereas others are compatible with life (summary by Huber and Cormier-Daire, 2012 and Schmidts et al., 2013). There is phenotypic overlap with the cranioectodermal dysplasias (Sensenbrenner syndrome; see CED1, 218330). For a discussion of genetic heterogeneity of short-rib thoracic dysplasia, see SRTD1 (208500).

A rare congenital distal limb malformation with complete and bilateral syndactyly between the fourth and fifth fingers. In most cases, it is a soft tissue syndactyly, but occasionally the distal phalanges may be fused. The feet are not affected. Inherited in an autosomal dominant manner.

The DDOD syndrome is characterized by autosomal dominant inheritance of congenital deafness and onychodystrophy. Conical, hypoplastic teeth is also a feature (Robinson et al., 1962). See also DOOR syndrome (220500), an autosomal recessive disorder, which includes congenital deafness, onychodystrophy, osteodystrophy, and mental retardation.