先天性无虹膜患者Pax6基因突变筛查

背景 先天性无虹膜是一种罕见的先天性常染色体显性遗传疾病,表现为双眼无虹膜,目前已知配对盒基因6(Pax6)突变与先天性无虹膜相关. 目的 对先天性无虹膜患者进行Pax6基因突变筛查.方法 纳入2012年8月至2015年10月在天津市眼科医院就诊的先天性无虹膜患者11例,包括来自3个先天性无虹膜家系的6例患者及5例散发病例,所有患者均接受常规眼科检查.采集所有患者的外周静脉血各3 ml,按照DNA分离试剂盒说明书描述的标准流程提取DNA,对Pax6和Elp4基因全部外显子、外显子5'和3'端与内含子拼接部序列、SIMO序列进行PCR扩增,采用Sanger直接测序法以及多重连接探针扩增技术(MLPA)对患者的Pax6基因进行序列分析,并与500例无眼前节异常的眼外伤患者的测序结果进行比对.结果 所有患者均虹膜缺如,视力为手动/眼前,1例患者存在晶状体脱位.直接测序结果发现,AN-01家系中的3例患者均携带Pax6基因c.688g＞t(p.E230X)突变,5例散发病例中3例携有Pax6基因突变,分别为c.468g＞a(p.W156X)、c.613c＞t(p.Q205X)和c.141+2t＞c突变,其中c.688g＞t (pE230X)为新发现的突变.AN-02家系的1例患者、AN-03家系的2例患者及另2例散发病例经直接测序和MLPA验证,均未发现Pax6、Elp4基因以及SIMO片段的突变.500名正常个体均未发现上述突变.结论 先天性无虹膜可由Pax6基因突变引起,c.688g＞t(p.E230X)为新发现的Pax6突变体,扩大了Pax6基因突变谱.

Mutation analysis of Pax6 in Chinese patients with congenital aniridia

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.