PAX6 and isolated aniridia: Furthermore, aniridia is a panocular syndrome that affects the cornea, anterior chamber, iris, lens, retina, macula and optic nerve.1 Approximately 66% of aniridia cases are familial, while 33% are sporadic.2 However, 90% of aniridia cases are related to PAX6 gene mutations, regardless of familial or sporadic status.3 Single allele mutations seem to be haploinsufficient for some cells and tissue.