Frizzled-9

Frizzled-9 (FZD9) is another gene located in the Williams-Beuren syndrome deletion region at 7q11.23, and its haploinsufficiency is thought to contribute to features of the syndrome, including cardiac abnormalities. The receptor couples Wnt ligand binding at its extracellular CRD to beta-catenin-dependent and planar cell polarity outputs through Dishevelled. Studies in mice have implicated Fzd9 in the development of cardiac hypertrophy, where it participates in Wnt signaling reactivated in stressed cardiomyocytes. FZD9 is expressed in heart, kidney, ovary and hematopoietic cells and has been detected in chronic lymphocytic leukemia and certain solid tumors. Its restricted expression and disease linkage make Frizzled-9 an appealing antibody target and a tool for probing Wnt biology in cardiovascular disease.