Iridogoniodysgenesis, Type 2

Clinical Characteristics
Ocular Features: 

The iris stroma is hypoplastic resulting in a usually dark chocolate color which can suggest the diagnosis at birth.  It may, however, appear slate gray in lightly pigmented individuals.  The pupil is usually normal in morphology and location.  Glaucoma may detectable in the newborn period but it may also not be diagnosed until the 4th decade or later.  It is widely accepted that the anterior chamber angle is anomalous but the architectural and cellular details are lacking.

Systemic Features: 

No systemic abnormalities have been described.


This is an autosomal dominant disorder resulting from heterozygous mutations in the PITX2 gene (4q25).

The same gene may be mutated in ring dermoid of the cornea (180550), Axenfeld-Rieger syndrome 1 (180500), Peters anomaly (604229), and in Axenfeld-Rieger anomaly plus (109120).

Type 1 iridogoniodysgenesis (IRID1) (601631) has many clinical similarities but is caused by DNA alterations in the FOXC1 gene.

Treatment Options: 

Glaucoma is the most frequent result of the anterior chamber dysgenesis in IRID2.  It is often difficult to control.  Early detection is of the utmost importance and all members of at-risk families require lifelong surveillance.

Article Title: 


Alward WL, Semina EV, Kalenak JW, Heon E, Sheth BP, Stone EM, Murray JC. Autosomal dominant iris hypoplasia is caused by a mutation in the Rieger syndrome (RIEG/PITX2) gene. Am J Ophthalmol. 1998 Jan;125(1):98-100.

PubMedID: 9437321