COL2A1 and Hip dysplasia: Notably, DDH is increasingly being reported as one of the features of the syndrome, and additional gene variants were detected that may be associated with DDH besides the above-mentioned variants in HSPG2 (Yu et al., 2022), TBX1 (Weisfeld-Adams et al., 2012), COL1A1, COL1A2 (Ayoub et al., 2020), COL2A1 (Agenbag et al., 2020), and COL27A1 (Frigola et al., 2021) (Table 2; Table 3).