By contrast, missense mutations usually exhibit a moderate impact on PAX6 functionality and are often associated with some atypical PAX6-associated phenotypes, such as mild forms of iris coloboma or isolated foveal hypoplasia, or more severe phenotypes of Peter’s anomaly and microphthalmia (Hanson et al., 1999; Azuma et al., 2003; Nallathambi et al., 2006; Jia et al., 2010; Thomas et al., 2014). This evidence concerns the gene PAX6 and microphthalmia.