Identification of a Non-Stop Mutation in PAX6 Causing a Unique Presentation of Aniridia in an Iranian Family Trial

Abstract

Non-syndromic aniridia (iris hypoplasia) as an autosomal dominant eye disorder results from the chromosomal abnormalities and mutations within the paired box gene 6 (PAX6). The aim of this study was to investigate on the clinical and the underlying genetic alteration in PAX6 gene in a large pedigree with five generations of Iranian family with an autosomal dominant aniridia. Here, we reported unique clinical features in terms of presenting nystagmus, ptosis, minimal iris abnormality, foveal hypoplasia and late-onset clinical limbal stem cell deficiency. Genomic DNA was extracted from the affected members and polymerase chain reaction (PCR) was conducted using specific primers to amplify coding sequence of PAX6. Then, PCR products were subjected to bidirectional dye terminator sequencing. A heterozygous transversion mutation A→T (c.1268A>T, p.*423Lext*15) in exon 13 of PAX6 was identified in all affected individuals, but not in the healthy members. This is the first report of non-stop mutation in PAX6 gene in an Iranian family accompanied with an isolated form of unusual congenital aniridia running within this family.