PAX6 gene analysis in irido-fundal coloboma

To screen the paired box gene 6 (PAX6) gene in irido-fundal coloboma.

The entire coding region of PAX6 including intron-exon boundaries was amplified from cases (n=30) and controls (n=30). All sequences were analyzed against the ensemble sequence (ENSG00000007372) for PAX6.

DNA sequence analysis of patients and controls revealed a total of three nucleotide changes (g.31815391Cytosine>Thymine; Glycine72Glycine and g.31812215Thymine>Guanine) of which one was neutral/synonymous change and the remaining two were intronic changes. Of these 3 changes, 2 were novel and one was already reported change. All these changes were non-pathogenic, according to in silico analysis.

In our study no pathogenic PAX6 mutation were identified. This suggests involvement of other coloboma genes. This study expands the SNP spectrum of PAX6, only rare variations which are not causative have been found. Since this is a pilot study in the north Indian population, results should be confirmed in different populations by similar studies. Familial cases are required for determining the underlying genetic loci accounting for this clinical phenotype and may lead to better understanding of disease pathogenesis.