Other reports have described adolescent rickets of FHH patients, which is mainly attributed to elevated PTH or vitamin D deficiency.2,3 However, in this study the vitamin D concentration (13.7–18.6 ng·mL−1) was approximated to the mean 25(OH)D level in the Chinese population (19.4±6.4 ng·mL−1 and 13.2±5.4 ng·mL−1).25,26 The elevated PTH, attributed to both FHH and secondary hyperparathyroidism induced by low concentration of 25(OH)D, may contribute to the clinical manifestation of rickets. Here, PTH is linked to familial hypocalciuric hypercalcemia.