078: Application of Next Generation Sequencing (NGS) technologies to the molecular diagnosis of inherited cardiac diseases

Abstract

Inherited cardiomyopathies and arrhythmias are autosomal dominant diseases with an important genetic heterogeneity. Their overall pre-valence, associated with the risk of sudden death, stress the need for high throughput and sensitive genetic diagnosis in order to improve genetic counseling and medical management. We evaluated the strength of Next Gene-ration Sequencing (NGS) technologies to fulfill these criteria through simultaneous sequencing of the major known causative genes described as responsible for these phenotypes. We designed a custom target capture system (Agilent) of 64 genes followed by high-throughput sequencing on HiSeq2000 (Illumina). Ten DNAs with mutations (in MYH7, MYBPC3, LMNA, FHL1, SCN5A, KCNH2, KCNQ1, DSG2, DSP and PKP2 genes) were included as control. Validation was done by evaluating capture efficiency, coverage deep, sequencing sensitivity and reproducibility. More than 90% of targeted sequences were fully covered (> 50X). After variants filtering, each DNA sample presented ~20 variations. Variants were classified according to multiple criteria such as allelic frequency, mutation type and functional effects. All 10 control mutations were identified. However 2 to 4 additional potential pathogenic variants were found in each individual. NGS based diagnostic is reliable in cardiac disorders. This technique should allow a sensitive, comprehensive, cost-effective and rapid molecular diagnosis of patients. However, our results underlined the complexity of the genetic profile of patients that should be taken into account into clinical practice.