Targeted Next Generation Sequencing as Diagnostic Tool in Pediatric Cardiomyopathy

Introduction: Pediatric cardiomyopathy is a heterogeneous disease with a strong genetic component. Molecular genetic analysis has recently been recommended for any symptomatic patient fulfilling the clinical diagnostic criteria. Here, we describe the evaluation of next generation sequencing technology for the comprehensive testing of 46 genes linked to hereditary cardiomyopathy.

Methods: We analyzed 48 DNA samples originating from cardiomyopathy patients, the majority of which suffered from familial HCM. The Illumina TrueSight Cardiomyopathy Panel was used for hybridization-based enrichment of target genes, followed by 150 bp paired-end sequencing on a MiSeq-platform. A proprietary workflow was developed to streamline the sequence-data analysis and to list and interpret variants.

Results: As expected, we detected causative mutations in commonly affected disease genes, namely, MYBPC3 and MYH7. In patients devoid of variants in these genes, mutations could be detected in rarely affected genes (e.g., TMEM43, MYOZ2). Additional variants suspected to cause or modify the disease were found in 40% of the patients.

Conclusions: We have successfully established a fast and cost-efficient genetic testing method for patients with cardiomyopathy. We detected mutations in patients with both classical and ambiguous phenotypes. Therefore, our approach may assist in the collection of information on both well-defined and unacquainted pediatric cardiomyopathic disorders and in revealing their true phenotypic spectrum.