目的:检测一个常染色体显性多囊肾家系的基因变异位点，并进行致病性功能验证。方法:采集先证者及其家属的外周血标本，提取血液基因组DNA，运用全外显子组测序手段对先证者进行基因变异分析，筛选候选基因变异位点，再用Sanger测序技术对所有家系成员进行验证，并在健康人群中筛查该变异。同时构建n PKD2基因的野生型和变异型真核表达载体，转染HEK293T和HeLa细胞，观察蛋白表达及细胞定位情况。n 结果:先证者存在n PKD2基因c.2051dupA(p.Tyr684Ter)移码变异，该变异使cDNA序列第2051位碱基A重复，导致终止密码子的形成，产生截短蛋白。免疫荧光实验显示，与野生型相比，变异型蛋白在细胞内的定位发生了改变，这种改变可能由n PKD2编码蛋白C端缺失引起。n 结论:PKD2基因c.2051dupA(p.Tyr684Ter)变异可能是该家系患者的致病原因。n “,”Objective:To detect the mutation site in a pedigree affected with autosomal dominant polycystic kidney disease (ADPKD) and verify its impact on the protein function.Methods:Peripheral blood samples were collected from the proband and his pedigree members for the extraction of genomic DNA. Mutational analysis was performed on the proband through whole-exome sequencing. Suspected variant was verified by Sanger sequencing. A series of molecular methods including PCR amplification, restriction enzyme digestion, ligation and transformation were also used to construct wild-type and mutant eukaryotic expression vectors of the n PKD2 gene, which were transfected into HEK293T and HeLa cells for the observation of protein expression and cell localization.n Results:The proband was found to harbor a c. 2051dupA (p. Tyr684Ter) frame shift mutation of the n PKD2 gene, which caused repeat of the 2051st nucleotide of its cDNA sequence and a truncated protein. Immunofluorescence experiment showed that the localization of the mutant protein within the cell was altered compared with the wild-type, which may be due to deletion of the C-terminus of the n PKD2 gene.n Conclusion:The c. 2051dupA (p. Tyr684Ter) mutation of the n PKD2 gene probably underlay the pathogenesis of ADPKD in this pedigree.n