A Novel Human PTH Analog Cys25hPTH(1–34) Restores Bone Mass in Ovariectomized Mice

CONTEXT: Recently, an arginine-to-cysteine homozygous mutation at position 25 in mature PTH was reported in a Korean patient with hypoparathyroidism. OBJECTIVE: To clarify whether the high bone mass phenotype observed in this patient was related to the hypoparathyroidism itself or to chronic elevation of mutant PTH. METHODS: hPTH(1-34). The peptides were then sc delivered to ovariectomized mice as daily single injections. RESULTS: hPTH(1-34) increased the bone formation rate in both trabecular and periosteal bones compared with the control group. CONCLUSION: The high bone mass phenotype observed in this patient with hypoparathyrodism caused by a Cys mutation at the 25th residue of hPTH(1-84) may have arisen from both direct and indirect effects exerted by the mutant PTH itself on bone.