Anterior Segment Dysgenesis 6

Background and History: 

The eye is often divided into anterior and posterior segments.  The anterior segment consists of structures such as the iris (colored part of the eye) and the cornea while the posterior segment is the portion that consists of the retina and the optic nerve.  While some gene mutations involve changes of the whole eye, others impact only certain structures.  The condition described here involves only the front of the eye and leads to malformations that impact the iris, the cornea, and the lens.   

Clinical Correlations: 

This is a congenital disorder in which the iris is incompletely developed which can result in distortions of the pupil.  The iris is thinner than normal and does not block light completely.  Adhesions of the iris to the cornea often occur and could result in increased pressure in the eye (glaucoma).  There can be scarring of the cornea (the clear windshield of the eye).


This is an autosomal recessive disorder resulting from mutations in both copies of a gene, one inherited from each parent.  Each offspring from two parents who each have one mutation confers a 25% chance that they will inherit this condition.

Diagnosis and Prognosis: 

The abnormal appearance of the iris at birth should suggest this disorder but it is not diagnostic since other genetic conditions may have similar abnormalities.  It is important to determine early if the pressure in the eye is too high in all such individuals since glaucoma can cause permanent damage to the eye.  Lifelong pressure monitoring is important since the intraocular pressure may increase in later life as well.

Pediatricians, ophthalmologists, neurologists, and orthopedists should be involved in the initial assessments because the ocular abnormalities may also be components of more complex conditions.

There is no cure for this syndrome.  However, if glaucoma is present there are pharmacologic and surgical treatments.  Corneal scarring might be treated with transplant surgery which may improve vision for selected individuals.

There does not seem to be an impact on longevity.

Additional Information
Autosomal recessive