Variant-specific disruption to Notch signaling in PAX6 microphthalmia and aniridia patient-derived hiPSC optic vesicles

The homeobox-containing transcription factor PAX6 is a key regulator of eye development. Pathogenic heterozygous PAX6 variants lead to variable ocular phenotypes. Missense variants are often associated with milder ocular conditions, although variants in the DNA-binding paired domain which alter target binding lead to severe ocular phenotypes including bilateral microphthalmia, similar to SOX2 anophthalmia syndrome. However, the variant-specific pathway disruption resulting in phenotypic heterogeneity is not well understood.