Published 27/05/2014
Aniridia
Sequencing of the PAX6 gene
Genes
(full coding
region): |
PAX6 |
Lab method: |
Sanger sequencing |
Specimen requirements: |
2-4 ml of blood with anticoagulant EDTA
500 ng DNA in TE, AE or pure sterile water at 100-250 ng/µl
The A260/A280 ratio should be 1.8-2.0. DNA sample should be run on an agarose gel as a single band, showing no degradation, alongside with a quantitative DNA marker. |
Deletion/duplication analysis
Specimen requirements: |
2-4 ml of blood with anticoagulant EDTA
1 µg DNA in TE, AE or pure sterile water at 100-250 ng/µl
The A260/A280 ratio should be 1.8-2.0. DNA sample should be run on an agarose gel as a single band, showing no degradation, alongside with a quantitative DNA marker. |
Indications for genetic testing:
- Confirmation of clinical diagnosis
- Genetic counseling
- Prenatal diagnosis for known familial mutation
Aniridia is characterized by complete or partial absence of the iris. The symptoms of the disease may include foveal hypoplasia, reduced visual acuity, nystagmus, photophobia, glaucoma, cataract, and optic nerve hypoplasia.
Aniridia can be isolated or as a part of the WAGR (Wilms tumor, aniridia, genital anomalies and mental retardation) syndrome.
The prevalence of aniridia is estimated between 1:50 000-1:100 000.
Isolated aniridia is caused by mutations in the PAX6 gene or deletion of a regulatory region controlling PAX6 expression. WAGR syndrome is caused by a deletion of chromosome 11p13, the region harboring the PAX6 and WT1 genes. Isolated aniridia and WAGR syndrome are inherited in an autosomal dominant manner.