Effects of PAX6 mutations on retinal function: an electroretinographic study.
OBJECTIVE
To investigate the retinal function in aniridic patients with documented PAX6 mutations to determine the range of electroretinogram abnormalities in aniridic patients and to relate electroretinogram findings with specific PAX6 mutations.


METHODS
Eleven patients with typical aniridia and fully characterized PAX6 mutations underwent electroretinography.


RESULTS
In all 11 patients, electroretinogram recordings were abnormal, ranging from mild to severe. Rod-related and cone-related activities were equally affected. The amplitude of the oscillatory potentials was the most reduced, followed by the b-wave, then to a milder degree the a-wave. Mutations affecting the paired domain of the PAX6 protein had the biggest impact on the electroretinogram amplitudes. Implicit times were increased in a subgroup with mutations affecting only the homeodomain.


CONCLUSIONS
Patients with aniridia have varying degree of retinal dysfunction, ranging from severely abnormal to almost normal. The paired domain appears to have more impact on retinal function than other regions of the PAX6 protein. It is unclear whether mutations affecting the homeodomain lead to alteration of the photoreceptor function.
Tremblay
F
F
Department of Ophthalmology, Dalhousie University and IWK Grace Health Centre, Halifax, Nova Scotia, Canada. ftrembla@is.dal.ca
Gupta
S K
SK
De Becker
I
I
Guernsey
D L
DL
Neumann
P E
PE
D000293:Adolescent; D000328:Adult; D015783:Aniridia / Q000235:genetics / Q000503:physiopathology*; D002648:Child; D004268:DNA-Binding Proteins / Q000235:genetics*; D004596:Electroretinography; D005136:Eye Proteins / Q000235:genetics*; D018398:Homeodomain Proteins; D006801:Humans; D007223:Infant; D008875:Middle Aged; D009154:Mutation; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D010641:Phenotype; D012097:Repressor Proteins; D012160:Retina / Q000503:physiopathology*
D004268:DNA-Binding Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; C000605730:PAX6 protein, human; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins