PAX6 Gene Function in Ocular Development and Disorders

PAX6 encodes a highly conserved transcription factor essential for vertebrate eye formation. Its dynamic expression within the developing optic cup, lens placode and corneal epithelium orchestrates cell proliferation, patterning and differentiation. As a dosage-sensitive master regulator, PAX6 activity is finely tuned by promoters, enhancers and other cis-regulatory elements distributed both upstream and downstream of the coding sequence. Heterozygous loss-of-function variants, including nonsense mutations and large deletions, result in PAX6 haploinsufficiency and give rise to aniridia, foveal hypoplasia, cataract, keratopathy and secondary glaucoma. Emerging genotype–phenotype correlations link specific classes of mutations—such as missense changes affecting the paired domain—to milder ocular anomalies, while disruption of long-range enhancers can cause positional effects leading to pan-ocular defects. Beyond congenital aniridia, PAX6 dysfunction is implicated in broader ocular malformations and contributes to the pathogenesis of syndromic conditions such as WAGR, in which contiguous deletions encompass PAX6 and adjacent genes. Recent methodological advances, from induced pluripotent stem cell-derived optic models to long-read genomic sequencing, are providing unprecedented insight into non-coding variants, splicing defects and structural rearrangements, with implications for diagnosis and therapeutic development.

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Research from all publishers

Innovative drug-repurposing studies using patient-derived induced pluripotent stem cell (iPSC) models of congenital aniridia have demonstrated that translational readthrough-inducing compounds can partially restore full-length PAX6 and ameliorate downstream transcriptional defects in three-dimensional optic cup and limbal epithelial cell assays. Functional assays combining minigene splicing constructs with nanopore-based long-read sequencing have uncovered pathogenic deep-intronic variants that activate cryptic splice sites, leading to pseudo-exon inclusion and further destabilisation of PAX6 transcripts. In parallel, comprehensive long-read genome sequencing has resolved cryptic structural rearrangements—such as inversions and balanced translocations disrupting distal enhancers—that eluded short-read platforms, confirming their role in PAX6 haploinsufficiency and expanding the known mutational spectrum. Collectively, these approaches underscore the importance of integrating cellular models and high-resolution genomic techniques to refine molecular diagnoses and pave the way for targeted interventions.

PAX6 Gene Function in Ocular Development and Disorders publication trend

The graph below shows the total number of articles in pax6 gene function in ocular development and disorders across all publications each year (not limited to Nature Index journals).

Technical terms

Haploinsufficiency: Insufficient gene dosage arising when one functional copy of a gene is not enough to maintain normal function.

Induced pluripotent stem cells (iPSCs): Somatic cells reprogrammed to a pluripotent state, capable of differentiating into multiple cell types.

Translational readthrough-inducing drugs (TRIDs): Compounds that promote bypass of premature termination codons, enabling translation of full-length proteins.

Deep-intronic variant: A mutation located within an intron far from canonical splice sites that can create or activate cryptic splice signals.

Long-read sequencing: Next-generation sequencing technology that generates extended DNA reads, facilitating the detection of complex structural variants.

Cis-regulatory element: Non-coding DNA sequence, such as an enhancer or promoter, that controls spatial and temporal gene expression.

References

1. Restoration of functional PAX6 in aniridia patient iPSC-derived ocular tissue models using repurposed nonsense suppression drugs. Molecular Therapy - Nucleic Acids (2023).
2. Minigene Splicing Assays and Long-Read Sequencing to Unravel Pathogenic Deep-Intronic Variants in PAX6 in Congenital Aniridia. International Journal of Molecular Sciences (2023).
3. Long-read genome sequencing identifies cryptic structural variants in congenital aniridia cases. Human Genomics (2023).
4. The Spectrum of PAX6 Mutations and Genotype-Phenotype Correlations in the Eye. Genes (2019).
5. Long-range downstream enhancers are essential for Pax6 expression. Developmental Biology (2006).
6. The genetic architecture of aniridia and Gillespie syndrome. Human Genetics (2018).