Thus, bone resorption is favored leading to a negative calcium balance and bone loss.28,29 In addition, serum levels of bone turnover markers, such as ALP and osteocalcin, are elevated and could remain high for a few months after treatment of hyperthyroidism and normalization of serum thyroid hormones.30 In our case, concentrations of ALP remained high for several years due to undiagnosed central hyperthyroidism. This evidence concerns the gene TG and hyperthyroidism.