Platyspondylic lethal skeletal dysplasia, Torrance type (PLSDT; MIM 151210) is an autosomal dominant disorder caused primarily, if not exclusively, by mutations in the C-propeptide domain of COL2A1. PLSDT is a neonatal short-limbed dwarfism disorder that is usually lethal. Patients typically display macrocephaly, short necks, midface hypoplasia or cleft palate. The thorax is small and narrow and the ribs are short with splayed ends. There is shortening of the long bones with splayed metaphyseal margins, platyspondyly with wafer-like vertebral bodies, iliac hypoplasia with medial spur and brachydactyly. Bowing of long bones may also be a feature. PLSDT is clinically similar to spondyloperipheral dysplasia , another disorder caused by mutations in the C-propeptide region of COL2A1. In some instances PLSDT patients have survived, but it has been suggested that these individuals may actually be affected by spondyloperipheral dysplasia.