Aniridia
Aniridia is an eye disorder characterized by a complete or partial absence of the colored part of the eye (the iris) and is usually associated with foveal hypoplasia (underdevelopment of the part of the eye responsible for sharp central vision). This combination can lead to decreased visual acuity and involuntary eye movements (nystagmus) in affected infants. People with aniridia may also have other eye problems including increased pressure in the eye (glaucoma), clouding of the lens of the eye (cataracts), and abnormalities of the cornea. Many of these eye problems contribute to progressive vision loss in affected individuals. Occasionally, people with aniridia have behavioral problems, developmental delay, and problems detecting odors. Aniridia may occur either as an isolated eye abnormality or as part of the Wilms tumor-aniridia-genital anomalies-retardation (WAGR) syndrome. Isolated aniridia may be caused by mutations in the PAX6 gene and is inherited in an autosomal dominant pattern.