CHD7 and coloboma: Specifically, heterozygous loss-of-function mutations in CHD7 (MIM 608892) are the main cause of CHARGE syndrome (MIM 214800), a multisystemic developmental disorder characterized by the association of coloboma, heart defects, atresia of choanae, retarded growth, genital defects, and ear abnormalities (Vissers et al., 2004).