The Spearman correlation coefficient (r) values denoting the association between lumbar spine T-score and serum DKK1 levels, as well as hip T-score and serum DKK1 levels among OI patients, were − 0.679 (p = 0.043) and − 0.689 (p = 0.042), respectively (Fig. 1). This evidence concerns the gene DKK1 and osteogenesis imperfecta.