PAX6 and isolated aniridia: Fourth, because human subjects in our study were recruited on the basis of having aniridia, all participants were, by definition, PAX6 haploinsufficient, and, therefore, we were unable to assess the effect of C11orf46+/− independent of PAX6+/− and the phenotype of isolated C11orf46+/− is unknown (although homozygous mutations in C11orf46 have been reported in association with intellectual disability).