Identification of novel mutations of PKD1 gene in Chinese patients with autosomal dominant polycystic kidney disease by targeted next-generation sequencing.

BACKGROUND: Mutations of PKD1 and PKD2 accounted for the most cases of autosomal dominant polycystic kidney disease (ADPKD). The presence of the large transcript, numerous exons and complex reiterated regions within the gene has significantly complicated the analysis of PKD1 with routine PCR-based approaches.

METHODS: We developed a strategy to analyze both the PKD1/PKD2 genes simultaneously using targeted next-generation sequencing (NGS). All coding exons plus the flanking sequences of PKD1 and PKD2 genes from probands were captured, individually barcoded and followed by HiSeq2000 sequencing. The candidate variants were validated by using classic Sanger sequencing. PKD1-specific primers were designed to amplify the replicated areas of PKD1 gene.

RESULTS: Five novel variations and one known mutation in PKD1 gene were detected in five familial and one sporadic Chinese ADPKD patients. Through pedigree and bioinformatic analysis, five of them were identified as pathogenic mutations (p.G1319R, p.Y3781*, p.W4122*, p.Val700Glyfs*14, and p.Leu3656Trpfs*28) and one was as polymorphism (p.T2420I).

CONCLUSIONS: Our result showed that targeted capture and NGS technology were effective for the gene testing of ADPKD disorder. Mutation study of PKD1 and PKD2 genes in Chinese patients may contribute to better understanding of the genetic diversity between different ethnic groups and enrich the mutation database in Asian population.