GPRC6A and hyperphosphatemia: We observed a complex phenotype in GPRC6A−/− mice consisting of defective mineralization of bone and impaired osteoblast function in male and female mice, a decrease in lean body mass, an increase in fat mass, hyperphosphatemia and hypercalciuria, hyperglycemia and feminization of male mice associated with altered ratio of estradiol and testosterone, suggesting that GPRC6A participates in hormonal control of energy metabolism.