Genomic coordinate (human 11:31,789,026 PAX6) & (mouse 2:105,499,245 Pax6).
Cytoband (human 11p13 PAX6) & (mouse 2q Pax6).
Here I present: “Aniridia”, Victor McKusick, Mendelian Inheritance in Man’, 1966. (PAX6) icd10=Q13.1
Aniridia is a congenital (present at birth) pan-ocular disorder where the iris is partially or almost completely absent. Even though the name literally means “without iris,” it’s usually more than just the iris that’s affected.
🧬 Genetic Basis
Most commonly caused by mutations in the PAX6 gene
Located on chromosome 11p13
Can be:
Isolated (non-syndromic), or
Part of WAGR syndrome
👁️ Ocular Features
Aniridia often involves multiple parts of the eye:
Iris hypoplasia (underdeveloped iris)
Foveal hypoplasia → reduced visual acuity
Nystagmus (involuntary eye movement)
Photophobia (light sensitivity)
Cataracts
Glaucoma (often develops later)
Corneal pannus / aniridia-associated keratopathy (AAK)
Optic nerve hypoplasia (in some cases)
So clinically, it’s better thought of as a developmental eye disorder, not just an iris defect.
🧒 Inheritance Pattern
Usually autosomal dominant
~1/3 familial
~2/3 sporadic (new mutation)
If sporadic, doctors often check for deletion at 11p13 because of the tumor risk in WAGR.
⚠️ Associated Systemic Risk (when syndromic)
In WAGR syndrome:
Wilms tumor (kidney cancer risk)
Genitourinary anomalies
Developmental delay
This is why renal ultrasound screening is recommended in infants with new aniridia diagnosis.
There is evidence that Aniridia is caused by mutation in the paired box-6 (PAX6) gene encoded on genomic coordinate 11:31,789,026 and cytoband 11p13 humans.
