Although ocular involvement has to be discussed in this patient in context of the identified ARID1B variant, in Coffin-Siris syndrome ocular findings are more likely to manifest as strabismus, nystagmus, cataract, hypophoria, astigmatism, hypermetropia and anisomyopia [19], with optic nerve hypoplasia being described only occasionally [20]. This evidence concerns the gene ARID1B and pathologic nystagmus.