Diagnostic yield of clinical next-generation sequencing panels for epilepsy.

Diagnostic Yield of Clinical Next-Generation Sequencing Panels for Epilepsy During the past 2 years, next-generation DNA sequencing (NGS) has become a widespread diagnostic tool in neurology. Several studies have addressed the diagnostic yield and cost of NGS relative to other types of DNA testing. G-banded karyotyping identifies chromosomal aberrations and has a 3% diagnostic yield for unexplained developmental disabilities or other congenital anomalies.1 In comparison, chromosomal microarrays detect gene copy number variations and have a yield of 15% to 20% for the same disorder categories.1 Next-generation DNA sequencing, in the format of wholeexome sequencing (WES), can be diagnostic in 25% of neurogenetic cases.2 Similarly, whole-genome sequencing (WGS) with NGS has a reported diagnostic yield of 27% in children and adults with a broad variety of diseases.3 In contrast to WES andWGS, targeted NGS panels focus on subsets (dozens to hundreds) of genes associated with specific phenotypes. For example, targeted NGS directed at a single disease category, such as congenital glycosylation disorders, has a reported diagnostic yield of 14.8%.4 Given the prevalence of pediatric epilepsy, we set out to critically assess the diagnostic yield of an NGS panel for epilepsy in a pediatric tertiary care hospital.