COL2A1 and spondyloepiphyseal dysplasia congenita: In this study, variants of c.1654G>A in exon 25 and c.3518G>T in exon 50 of COL2A1 could induce amino acid substitutions (p.Gly552Arg and p.Gly1173Val) in the triple‐helical glycine residue, which were reported for the first time in COL2A1. p.Gly552Arg and p.Gly1173Val variants would damage the Gly‐X‐Y triplet sequence, which led to the degradation of premature collagen molecules, and led to abnormal bone and joints in patients with SEDC.