Abstract

Next Generation Diagnostics

Birgit Sikkema-Raddatz, Clinical Laboratory Geneticist, University Medical Center Groningen

The challenge in genetic diagnostics is to apply one comprehensive test for heterogeneous diseases. The number of genes to examine in a particular clinical case can be relatively large because phenotypes of many hereditary syndromes are known to overlap and different genes may underlie a single syndrome. Our aim was to design and implement various targeted next generation sequencing (NGS) gene-panels, starting with those disorders that account for the majority of current diagnostic requests. As proof of principle we developed a gene-panel based on Agilent Sure Select Target Enrichment® for simultaneous mutation detection of 48 genes associated with hereditary cardiomyopathies. Pools of 12 samples were sequenced on an Illumina MiSeq® sequencer and analyzed using NextGene® and Cartagenia-NGS® software. A validation to assess test-sensitivity and specificity was performed on 84 patients. Subsequently, an extended gene-panel targeting 55 cardiomyopathy-associated genes was implemented in routine diagnostics and more than 400 patients have been analyzed. In parallel, targeted NGS gene-panels for cancer predisposition genes, movement disorders, epilepsy and skin diseases were designed and validated in a similar manner. From these studies we are able to conclude that: (1) the quality of our targeted NGS-panels equals Sanger Sequencing; (2) our approach results in a significant increase in diagnostic yield.