Axenfeld-Rieger syndrome is primarily an eye disorder, although it can also affect other parts of the body. This condition is characterized by abnormalities of the front part of the eye, an area known as the anterior segment. For example, the colored part of the eye (the iris), may be thin or poorly developed. The iris normally has a single central hole, called the pupil, through which light enters the eye. People with Axenfeld-Rieger syndrome often have a pupil that is off-center (corectopia) or extra holes in the iris that can look like multiple pupils (polycoria). This condition can also cause abnormalities of the cornea, which is the clear front covering of the eye.

Axenfeld-Rieger syndrome results from mutations in at least two known genes, PITX2 and FOXC1. PITX2 gene mutations cause type 1, and FOXC1 gene mutations cause type 3. The gene associated with type 2 is likely located on chromosome 13, but it has not been identified. The proteins produced from the PITX2 and FOXC1 genes are transcription factors, which means they attach (bind) to DNA and help control the activity of other genes. These transcription factors are active before birth in the developing eye and in other parts of the body. They appear to play important roles in embryonic development, particularly in the formation of structures in the anterior segment of the eye.

Axenfeld-Rieger syndrome has an estimated prevalence of 1 in 200,000 people.

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

Published Date: November 01, 2019
Published By: National Institutes of Health