COL2A1 and achondrogenesis: Among patients with variants in the COL2A1 gene (OMIM: *120140) (n=13), ten were diagnosed with spondyloepiphyseal dysplasia congenita (OMIM: #183900) and spondyloepimetaphyseal dysplasia (OMIM: #184250), two with Stickler syndrome (OMIM: #108300), and one with achondrogenesis type II (OMIM: #200610).