Mutation analysis of Pax6 in Chinese patients with congenital aniridia / 中华实验眼科杂志

ABSTRACT

Background Congenital aniridia is a rare congenital autosomal dominant disease,which is shown as aniridia of double eyes,and the paired box gene 6 (Pax6) gene mutation is now known to be associated with congenital aniridia.Objective This study was to screen the Pax6 gene mutation in patients with congenital aniridia.Methods Eleven patients with congenital aniridia were enrolled in Tianjin Eye Hospital from August 2012 to October 2015,including 6 patients from 3 congenital aniridia family and 5 sporadic patients.All patients received routine ophthalmic examination.Peripheral venous blood of 3 ml was collected from the patients for DNA extraction according to the standard process of DNA isolation instructions,and all the exons of Pax6 gene,Elp4 gene,exon 5 ' and 3',intron splice sequence and SIMO sequence were amplified by PCR.Pax6 genes of the patients were sequenced using Sanger direct sequencing and multiplex ligation dependent probe amplification (MLPA) and compared with those of 500 ocular trauma patients.This study complied with Helsinki declaration,and written informed consent was obtained from each patient prior to any medical examination.Results Iris absence was found in all the patients,and the visions acuity was hand motion to 0.2.Lens dislocation was seen in 1 patient.Direct sequencing results found that three patients in AN-O1 family were c.688g＞t (p.E230X) mutation of Pax6 gene,and 3 of 5 sporadic patients carried c.468g＞a (p.W156X),c.613c＞t (p.Q205X) and c.141 +2t＞c mutant of Pax6 gene,and the c.688g＞t (pE230X) mutation was a novel-discovered mutation.No any mutation in Pax6,Elp4 gene and SIMO fragment was detected in 1 patient from AN-02 family,2 patients from AN-03 family and 2 sporadic patients by both direct sequencing and MLPA validation.No above-mentioned mutation was found in 500 normal individuals.Conclusions The mutation of Pax6 gene is a pathogenic mutation in congenital aniridia patients,and c.688g＞t (p.E230X) is a novel Pax6 mutant,which expanded the mutation spectrum of Pax6 gene.