[MIM*271600, MIM*184100] a skeletal dysplasia of later onset, usually in the second decade, characterized by short stature, flattening of the vertebrae, epiphysial involvement with bony fusion of the hip joint, premature osteoarthritis, and distinctive radiographic findings. Autosomal dominant [MIM*184100] and X-linked recessive [MIM*313400] forms exist, which are caused by a mutation in the SEDL gene on Xp.