Spondyloepiphyseal dysplasia tarda (SEDL) is a radiologically distinct, X-chromosome linked primary skeletal dysplasia characterised by disproportionate short-trunked short stature, dysplasia of the large joints (hip) and flattened thoracic and lumber vertebral bodies. Molecular basis for SEDL has been elucidated by the identification of various mutations (currently >30) in the SEDL gene from Xp22 region. The function of the SEDL protein is not known although it is speculated that it may participate in the ER-to-Golgi transport as part of a novel highly conserved multiprotein TRAPP complex.