Implementation of a gene capture panel for genetic diagnosis of cardiac disorders

MJ Fietz, J-L Ricciardi, F Faiz, E Edkins and K Carpenter

Department of Diagnostic Genomics, PathWest Laboratory Medicine, QEII Medical Centre, Nedlands, WA

Background: The Department of Diagnostic Genomics at PathWest has a long history in the provision of molecular diagnostic services for a range of genetic disorders. In 2012, it was one of the first Australian centres to introduce Massively Parallel Sequencing (MPS) technologies for diagnostic testing. Over the past 2 years, our use of MPS has expanded significantly, including the introduction of a specialist gene panel for the analysis of a broad range of cardiac disorders. Aim: To examine the efficacy of a commercial gene panel for the genetic diagnosis of cardiac disorders. Methods: Patient samples were examined using the 174-gene Illumina TruSight Cardio Sequencing Kit, which utilises capture probes for isolation of target sequences. Libraries were sequenced on an Illumina MiSeq Desktop Sequencer with alignment and variant calling performed using BWA-MEM and GATK, respectively. Variant analysis was performed with Cartagenia Bench Lab NGS and Alamut Visual. Results: The Cardio Sequencing Kit yields at least 20-fold coverage for greater than 99% of target sequences, with a mean coverage across all currently tested samples of 400-fold. Validation with known control samples demonstrated efficacy in detection of single nucleotide variants and indels of up to 36bp in length. Complete analysis of 150 diagnostic patient samples has detected a clinically significant variant in 23% of cases, with 30% of structural disorders yielding a clinically significant variant. Conclusion: The use of a specialist gene panel for cardiac disorders has enabled the efficient analysis of a large range of relevant genes and proved highly effective in the detection of significant genetic variants.