What are the other Names for this Condition? (Also known as/Synonyms)

• Goniodysgenesis Hypodontia
• Iridogoniodysgenesis with Somatic Anomalies
• Rieger Syndrome

What is Axenfeld-Rieger Syndrome? (Definition/Background Information)

• Axenfeld-Rieger Syndrome (ARS) is predominantly an eye condition that involves the cornea and iris. However, individuals with this genetic syndrome can also present systemic signs and symptoms involving other body parts such as the face, skin, and heart
• Axenfeld-Rieger Syndrome forms part of a group of disorders named anterior segment developmental anomalies (ASDA). ASDA refer to a group of developmental disorders that involve the anterior segment region of the eye. These disorders are also termed anterior segment dysgenesis (ASD). The anterior segment anatomical region includes the cornea, lens, iris, and aqueous humor that nourishes the eye

Who gets Axenfeld-Rieger Syndrome? (Age and Sex Distribution)

• Axenfeld-Rieger Syndrome is a rare congenital disorder. The presentation of symptoms may occur following the birth of the child
• Both males and females may be affected
• Worldwide, individuals of all racial and ethnic groups may be affected

What are the Risk Factors for Axenfeld-Rieger Syndrome? (Predisposing Factors)

• A positive family history is an important risk factor, since Axenfeld-Rieger Syndrome is typically inherited

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Axenfeld-Rieger Syndrome? (Etiology)

• Axenfeld-Rieger Syndrome is a genetic disorder that is inherited in an autosomal dominant manner
• It forms part of a group of conditions that are known as anterior segment developmental anomalies (ASDA)

In individuals with ASDA, frequent disruptions in the aqueous humor production and drainage pathways result in complications, such as increased intraocular pressure, and consequently glaucoma.

There are three types of Axenfeld-Rieger Syndrome based on the specific type of gene involved:

• Axenfeld-Rieger Syndrome type 1 - PITX2 gene mutations are noted
• Axenfeld-Rieger Syndrome type 2 - it involves genetic mutations on chromosome 13; the exact gene that is involved remains unidentified
• Axenfeld-Rieger Syndrome type 3 - FOXC1 gene mutations are noted

Syndromic Axenfeld-Rieger Syndrome is caused by maldevelopment of the neural crest cells occurring during fetal growth and development.

Autosomal dominant mode of inheritance: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.

What are the Signs and Symptoms of Axenfeld-Rieger Syndrome?

The signs and symptoms of Axenfeld-Rieger Syndrome may vary from one individual to another, and it may be mild or severe. These include:

• Eye signs and symptoms:
  • Cloudy cornea
  • Small or large pupils
  • Off-center pupil (corectopia)
  • Appearance of multiple pupils (polycoria)
  • Iris hypoplasia
  • Glaucoma - noted in over half of the cases
  • Strabismus
  • Cataracts
  • Presence of posterior embryotoxon (opaque corneal ring)
• Other signs and symptoms may include:
  • Small teeth (microdontia) with abnormal spacing
  • Cone-shaped teeth
  • Missing teeth
  • Underdeveloped jaw
  • Pronounced lower lip
  • Eyes that are spaced apart
  • Extra skin folds around the stomach/abdomen
  • Narrow anal opening
  • Growth delays

How is Axenfeld-Rieger Syndrome Diagnosed?

Axenfeld-Rieger Syndrome may be diagnosed by the following observations and tests:

• Physical examination and medical history evaluation
• Assessment of the presenting signs and symptoms
• General eye exam
  • Fundoscopic (ophthalmoscopic) examination by an eye specialist, who examines the back part of the eye (or the fundus)
  • Visual acuity test using a special and standardized test chart (Snellen chart)
  • Slit-lamp examination
  • Gonioscopy, a painless eye exam using special devices
  • Visual evoked potential (VEP) test
• Neurological examinations
• Prenatal tests and newborn screening
• Laboratory tests, as relevant
• Imaging studies including CT and MRI scans of the head and neck region
• Molecular genetic testing
• Biopsy studies, if necessary

Tests and procedures to diagnose the associated condition, if any present, are important.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Axenfeld-Rieger Syndrome?

The complications of Axenfeld-Rieger Syndrome may include:

• Emotional stress for the parents and caregivers
• Macular degeneration
• Coloboma
• Permanent vision loss
• Hearing loss
• Heart defects
• Umbilical hernia
• Undescended testicles
• Mental health issues (rarely)
• Severe birth defects

How is Axenfeld-Rieger Syndrome Treated?

The treatment measures for Axenfeld-Rieger Syndrome may include:

• Symptomatic management of the condition is very important
• Decrease intraocular pressure to minimize risk of glaucoma through eye drops and medications; surgery may be necessary if the condition is severe
• Use of prescription eye glasses or contact lenses may be beneficial following treatment/surgery
• Laser surgery to treat eye symptoms, facial, dental and heart defects, as necessary to correct the abnormalities
• Administration of growth hormones

How can Axenfeld-Rieger Syndrome be Prevented?

Currently, there are no specific methods or guidelines to prevent Axenfeld-Rieger Syndrome since it is a genetic condition.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such as anterior segment developmental anomalies

What is the Prognosis of Axenfeld-Rieger Syndrome? (Outcomes/Resolutions)

• The prognosis of Axenfeld-Rieger Syndrome depends on the severity of the condition and one’s response to treatment. An early diagnosis and prompt medical intervention can help improve outcomes
• Individuals with mild conditions have better prognosis than those with severe symptoms and complications. Typically, the prognosis may be assessed on a case-by-case basis

Additional and Relevant Useful Information for Axenfeld-Rieger Syndrome:

Please visit our Eye & Vision Health Center for more physician-approved health information:

https://www.dovemed.com/health-topics/vision-center/