[Analysis of PKD2 gene variant and protein localization in a pedigree affected with polycystic kidney disease].

Cheng, Jianping; Li, Ping; Li, Yujun; Zhou, Yong'an; Ren, Ruirui; Han, Yaxin; Li, Xingxing; Li, Zhe; Bai, Yuan

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 PKD2 gene, which were transfected into HEK293T and HeLa cells for the observation of protein expression and cell localization. RESULTS The proband was found to harbor a c.2051dupA (p. Tyr684Ter) frame shift mutation of the 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 PKD2 gene. CONCLUSION The c.2051dupA (p. Tyr684Ter) mutation of the PKD2 gene probably underlay the pathogenesis of ADPKD in this pedigree.