CHST3 and spondyloepiphyseal dysplasia: Furthermore, many clinical features are common to spondyloepiphyseal dysplasia, Omani type, or humerospinal dysostosis other well-described entities caused by defects in CHST3 [Hermanns et al., 2008; Thiele et al, 2004; Van Roij et al., 2008].