g., the epilepsies, as well as other neurological and non-neurological conditions) may be a collection of rare and often private genomic disorders due to mutations in genetically intolerant genes (Petrovski et al., 2013). The International League Against Epilepsy classification of epilepsy includes information about seizure type, age of onset, response to antiepileptic drugs, electroencephalogram (EEG) and structural brain imaging information, and prognostic considerations. From a molecular and physiological perspective, however,

it is clear that this scheme often bears little selleck chemicals relationship with underlying biology. Copy-number variants are associated with a range of epilepsy subtypes (Heinzen et al., 2010), including focal

epilepsy, which responds to surgery (Catarino et al., 2011); causal Cilengitide molecular weight mutations in SCN1A show very complex genotype-phenotype relationships ( Zuberi et al., 2011); and mutations in the gene encoding DEPDC5 are responsible for a significant proportion of cases of familial nonlesional focal epilepsy ( Dibbens et al., 2013). The National Academies has recently recognized the need for “a new taxonomy of human disease based on molecular biology” in its publication Toward Precision Medicine ( National Research Council (US) Committee on A Framework for Developing a New Taxonomy of Disease, 2011). NGS can facilitate individualized molecular diagnoses in patients and families with hitherto undiagnosed out and unexplained disorders. The traditional diagnostic model in the evaluation of an individual with a putative genetic disorder includes formulation of a diagnostic hypothesis that may include a diverse range of possibilities. These possible diagnoses are then tested by a variety of biochemical (blood, urine, cerebrospinal fluid [CSF]), structural (MRI), functional (EEG), and specific gene analyses. A recent study examined the economic implications of WES-based diagnosis in the context of 500 patients evaluated using traditional genetic tests ( Shashi et al., 2013). This work showed that if the diagnosis is not clinically apparent at the first visit, then the cost on average per

successful genetic diagnosis using traditional tests is approximately $25,000. The cost of WES, on the other hand, is now well under $1,000 per sample. Thus, when used in an appropriate setting, WES has the potential to provide significant cost benefit to the healthcare budget and to society. Diagnostic sequencing should, and probably will, find wide, immediate application in the care of patients with neurological disease. The realization of its full potential will require addressing a number of key bottlenecks. Of particular importance is the challenge of data integration. Clearly, to maximize the benefit of WES-based diagnostics, it is critical to be able to compare the sequences of patients evaluated in different academic medical centers.