Similarly, the ER export of procollagen is also controlled in part by the ubiquitously expressed Sedlin (TrappC2), and antimorphic or loss of function mutations in TRAPPC2 cause X-linked spondyloepiphyseal dysplasia Tarda (SEDT) [33]. This evidence concerns the gene TRAPPC2 and spondyloepiphyseal dysplasia tarda, X-linked.