Frizzled Homolog 9 (FZD9)

The FZD9 gene is located within the Williams syndrome common deletion region of chromosome 7, and heterozygous deletion of the FZD9 gene may contribute to the Williams syndrome phenotype. FZD9 is expressed predominantly in brain, testis, eye, skeletal muscle, and kidney. In mouse, the wg-homologous Wnt1 gene is involved in early development of a large domain of the central nervous system encompassing much of the midbrain and rostral metencephalon.The potential function of FZD9 in transmitting a Wnt protein signal in the human brain and other tissues suggested to Wang et al. (1997) that heterozygous deletion of the FZD9 gene could contribute to the Williams syndrome phenotype.