Aniridia

Definition

• Aniridia is a rare congenital absence or severe hypoplasia of the iris (the colored part of the eye).
• The iris may be partially present or nearly completely missing.

Pathophysiology

• Caused by mutations or deletions in the PAX6 gene (chromosome 11p13).
• May occur isolated or as part of a syndrome.

Clinical Features

• Reduced visual acuity, nystagmus, photophobia, strabismus.
• Often associated with:
  • Cataracts
  • Glaucoma
  • Keratopathy
  • Foveal hypoplasia → poor central vision

Oncology Relevance

• Aniridia is a key feature of WAGR syndrome:
  • Wilms tumor (nephroblastoma)
  • Aniridia
  • Genitourinary anomalies
  • Retardation (intellectual disability)
• Patients with aniridia + WT1 gene mutations are at significantly higher risk for developing nephroblastoma (Wilms tumor).

Key Point for Oncology Pharmacists:

When you see aniridia in a child, think of possible WAGR syndrome and increased Wilms tumor risk — these patients need close monitoring and early intervention.