Studies in Europe indicate that the main genes involved in DDH pathology are genes for IL-6 (interleukin 6) [52], TGFB1 (transforming growth factor beta 1 or TGF-β1) [52] and GDF5 (growth differentiation factor 5 or cartilage-derived morphogenetic protein 1) [49]. Here, TGFB1 is linked to Hip dysplasia.