Genetics of calcium-sensing--regulation of calcium levels in the body.

The skeleton contains over 200 bones, with the regulation of calcium being vital for maintaining this dynamic tissue. The calcium-sensing receptor (CASR) plays a pivotal role in the regulation of calcium both systemically through the parathyroid and locally in specific tissues. Recent studies have identified several sites of expression and further functions for the CASR gene, which include a role in the epidermis, tooth development and fluid regulation. In addition, genetic studies have identified gain-of-function mutations in the CASR gene, leading to a greater understanding of the pathogenesis of Bartter's syndrome, an inherited nephropathy that results in deficiency of sodium and chloride absorption.