SHH and microphthalmia: HPE-causative mutations in SHH, including in the C-terminal region, as well as mutations in other pathway effectors can also lead to more subtle defects not always diagnosed in addition to uveal and chorioretinal coloboma and microphthalmia, including refraction errors induced by myopia, retinal thinning, malposition of the optic nerve, and borderline microcornea (Pineda-Alvarez et al. 2011).