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Aniridia Syndrome

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We present the following informational pages as a way to help our visitors learn more about Aniridia Syndrome issues.

  • What Is ANIRIDIA
    Defines Aniridia including some key word definitions.
  • Syndrome Conditions
    Describes conditions related to Aniridia and low vision.

What is Aniridia?

Aniridia by definitional terms means congenital absence or partial absence of the iris. However this is not the only feature of Aniridia, as will be discussed later.

Aniridia is rare. Its incidence is between 1/50,000 and 1/100,000. The genetic defect has been found to be a deletion on chromosome 11. It is anautosomal dominant  condition in 2/3 of the cases. Approximately, a third of all cases of Aniridia are sporadic and these are often found to have  cytogentically detectable deletions involving 11p13, which, if extensive enough, cause the WAGR contiguous gene syndrome.

As stated above, Aniridia is more than just being born without an Iris. Many aniridics have developmental and ocular abnormalities and may exhibit the presence of one or more of these associated ocular abnormalities:

  • cataract
  • lens dislocation
  • foveal dysplasia
  • optic nerve hypoplasia
  • corneal pannus
  • glaucoma
  • nystagmus

all of which contribute to severe reduction in visual acuity.

For more detailed information on the subject of Aniridia, its associated conditions, and new research, please go to the Members’ Area. If not currently a member, please register now so you can get the full benefit of the Aniridia Foundation Internationals resources.

Wilms Tumor
A malignant kidney tumor usually appearing before age 6, but rare cases have seen it appear later. Most authorities seem to agree on a 3 month interval of ultrasound monitoring during the period of greatest risk, (birth to age 5) with a 6 month to 1 year interval thereafter. Consult your doctor.

Condition Library

This section contains information about the collection of vision and/or medical conditions that are related to Aniridia.

WAGR Syndrome
WAGR Syndrome is a rare syndrome that is caused by a deletion on the 11th chromosome in 11p13 region of the PAX6 gene. WAGR is an acronym for the syndrome conditions possible in various arrangements. These conditions which make up the diagnosis of WAGR Syndrome are Wilms’ Tumor (cancerous tumor of the kidneys), Aniridia (absence of the iris-colored part of the eye), Genitourinary abnormalities (genital and urinary problems, possibly including gonadblastoma, cancer of the ovaries or testes), and Retardation. Recently in some cases an O has been added as a subset of WAGR referring to childhood obesity in some patients with WAGR.

When a newborn child has a diagnosis of aniridia further genetic testing needs to be done to see if the child does in fact have the 11p13 deletion causing WAGR. It is very rare for a WAGR patient to not have aniridia, but some cases have been found where the patient does not have aniridia. In WAGR patients about 50% develop Wilms’ tumor. Recently it has been shown that mutations on the PAX6 gene may not only cause ocular malformations, but also brain and pancreas problems. Furthermore, it has been proposed that the BDNF gene (which is located on 11p14.1 of the PAX6) is a candidate for the obesity and overeating in WAGR patients. Children with WAGR need to have routine (every three months) renal ultrasounds to check for Wilms’ tumor until the age of eight. After this age patients may have follow ups as a precaution against late onset nephropathy (disease of the kidneys).

For more detailed information on WAGR Syndrome go to The International WAGR Syndrome Association at