- 著者
-
Keiichi Ozono
Toshimi Michigami
Noriyuki Namba
Shigeo Nakajima
Takehisa Yamamoto
- 出版者
- The Japanese Society for Pediatric Endocrinology
- 雑誌
- Clinical Pediatric Endocrinology (ISSN:09185739)
- 巻号頁・発行日
- vol.15, no.4, pp.129-135, 2006 (Released:2006-11-03)
- 参考文献数
- 45
- 被引用文献数
-
3
3
Serum phosphate levels are regulated in both calcium-dependent and -independent fashions. Active vitamin D increases while PTH decreases serum phosphate levels in association with the elevation of serum calcium. On the other hand, a calcium-independent phosphaturic factor, historically called phosphatonin is believed to exert a physiological function based on findings in hereditary and tumor-induced diseases characterized by hypophosphatemia with normocalcemia. Among them, autosomal dominant hypophosphatemic rickets (ADHR) has contributed greatly to its elucidation because the gene responsible for ADHR encodes fibroblast growth factor 23 (FGF23) that has been found to have a phosphaturic effect. In addition, FGF23 has been proved to be involved in most cases of oncogenic osteomalacia and X-linked hypophosphatemic rickets that are also characterized by hypophosphatemia and normocalcemia. Moreover, familial tumoral calcinosis, which represents the metabolic mirror image of hypophosphatemic conditions, is caused by a loss-of-function mutation in the FGF23 gene in some patients. Very recently, hereditary hypophosphatemic rickets with hypercalciuria has been found to be caused by mutations in the SLC34A1 gene which encodes a type of sodium phosphate cotransporter. These findings may provide new strategies for treating patients with abnormal phosphate metabolism.