Fibroblast growth factor 23

Fibroblast growth factor 23 or FGF23 is a protein that in humans is encoded by the FGF23 gene. FGF23 is a member of the fibroblast growth factor (FGF) family which is responsible for phosphate metabolism.

Function

FGF family members possess broad mitogenic and cell survival activities and are involved in a variety of biological processes including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. The product of this gene inhibits renal tubular phosphate transport. FGF23 is known as a phosphaturic hormone, in that it inhibits renal reabsorption of phosphate in the kidney, mostly in the proximal convoluted tubule. FGF23 is mostly expressed in bone and connective tissue and prior to 2000 was known in the scientific community as phosphatonin. The factor itself was hypothesized following case studies of hypophosphatemic diseases such as X-linked hypophosphatemic rickets, autosomal dominant hypophosphatemic rickets and (tumor induced) oncogenic osteomalacia. Also, FGF23 inhibits 1-hydroxylase. 1-hydroxylase is responsible for the conversion of calcifediol to calcitriol (the biologically active form of Vitamin D).

Clinical signficance

FGF23 is located on chromosome 12 and is composed of three exons. Mutations in FGF23 that render the protein resistant to proteolytic cleavage leads to increased activity of FGF23 and the renal...
Read More