PAX6 gene variations associated with aniridia in south India

<p>Abstract</p> <p>Background</p> <p>Mutations in the transcription factor gene <it>PAX6 </it>have been shown to be the cause of the aniridia phenotype. The purpose of this study was to analyze patients with aniridia to uncover <it>PAX6 </it>gene mutations in south Indian population.</p> <p>Methods</p> <p>Total genomic DNA was isolated from peripheral blood of twenty-eight members of six clinically diagnosed aniridia families and 60 normal healthy controls. The coding exons of the human <it>PAX6 </it>gene were amplified by PCR and allele specific variations were detected by single strand conformation polymorphism (SSCP) followed by automated sequencing.</p> <p>Results</p> <p>The sequencing results revealed novel <it>PAX6 </it>mutations in three patients with sporadic aniridia: c.715ins5, [c.1201delA; c.1239A>G] and c.901delA. Two previously reported nonsense mutations were also found: c.482C>A, c.830G>A. A neutral polymorphism was detected (IVS9-12C>T) at the boundary of intron 9 and exon 10. The two nonsense mutations found in the coding region of human <it>PAX6 </it>gene are reported for the first time in the south Indian population.</p> <p>Conclusion</p> <p>The genetic analysis confirms that haploinsuffiency of the <it>PAX6 </it>gene causes the classic aniridia phenotype. Most of the point mutations detected in our study results in stop codons. Here we add three novel <it>PAX6 </it>gene mutations in south Indian population to the existing spectrum of mutations, which is not a well-studied ethnic group. Our study supports the hypothesis that a mutation in the <it>PAX6 </it>gene correlates with expression of aniridia.</p