Anirdia-like phenotype caused by 6p25 dosage aberrations.

Axenfeld-Rieger spectrum (ARS) includes the anterior segment abnormalities posterior embryotoxon, irido-corneal adhesions, corectopia, and other abnormalities of pupil size and shape. Glaucoma occurs in approximately 50% of affected children. It is often caused by mutations of FOXC1 or PITX2. Timing of expression and dosage of these transcription factors appear to be very critical in the development of the anterior segment. We report on one child with a deletion and another with a duplication involving 6p25, causing an anirdia-like phenotype. Classic anirdia is a pan-ophthalmic disorder caused by heterozygous mutations involving the paired homeobox gene PAX6 at 11p13. It is often associated with optic nerve hypoplasia, foveal hypoplasia, corneal pannus, nystagmus, and cataract. Microdeletion of 11p13 may be associated with life threatening Wilms tumor. Distinguishing these two syndromes has critical implications for prognosis and treatment. We demonstrate how chromosomal microarray can be instrumental in differentiating these phenotypes.