Targeted long-read sequencing enables higher diagnostic yield of ADPKD by accurate PKD1 genetic analysis

Genetic diagnosis of ADPKD has been challenging due to the variant heterogeneity, presence of duplicated segments, and high GC content of exon 1 in PKD1. In our reproductive center, 40 patients were still genetically undiagnosed or diagnosed without single-nucleotide resolution after testing with a short-read sequencing panel in 312 patients with ADPKD phenotype. A combination of long-range PCR and long-read sequencing approach for PKD1 was performed on these 40 patients. LRS additionally identified 10 pathogenic or likely pathogenic PKD1 variants, including four patients with microgene conversion (c.160_166dup, c.2180T>C, and c.8161+1G>A) between PKD1 and its pseudogenes, three with indels (c.-49_43del, c.2985+2_2985+4del, and c.10709_10760dup), one with likely pathogenic deep intronic variant (c.2908-107G>A) and two with large deletions. LRS also identified nine PKD1 CNVs and precisely determined the breakpoints, while SRS failed to identify two of these CNVs. Therefore, LRS enables higher diagnostic yield of ADPKD and provides significant benefits for genetic counseling.