For example, defective function in COL2A1, encoding type II collagen, may results in spondyloepiphyseal dysplasia congenita (SEDC) that is rare chondrodysplastic condition characterized by skeletal deformities such as short-trunk dwarfism, odontoid hypoplasia, cervical spine subluxation, scoliosis, kyphosis, lumbar lordosis, coxa vara, genu valgum, clubfoot, pes planus, and metaphyseal changes (Zhang et al., 2015). The gene discussed is COL2A1; the disease is spondyloepiphyseal dysplasia congenita.