Rs12901499, within the SMAD3 locus, was positively associated with HSM4 (β 0.05, P 1.69 × 10−13), describing greater acetabular coverage and narrower femoral neck, and was also found to be protective of hip osteoarthritis (β −0.07, P 2.83 × 10−15). This evidence concerns the gene SMAD3 and osteoarthritis, hip.