In particular, the literature previously described the clinical case of two children, both carrying a nonsense mutation in the ADNP gene, showing intellectual disability and peculiar congenital eye anomalies [90], as well as another study which reported the case of an HVDAS-affected patient carrying a different ADNP gene mutation displaying convergent strabismus, astigmatism, hyperopia, unilateral iris coloboma and bilateral optic nerve coloboma [91]. This evidence concerns the gene ADNP and coloboma of optic nerve.