For them, simply knowing the real explanation for the underlying disorder can provide comfort, reassurance, and closure. The correct diagnosis can also facilitate the provision of appropriate state health and social services. Of course, the hope is that knowing the correct diagnosis will also allow a more targeted approach to future therapies as they are discovered. Early application of NGS can bring to a close an often previously tedious, expensive, and emotionally wrenching “diagnostic odyssey”; for all of the reasons listed above, the use of NGS is simply good medical practice. There are likely few therapeutic

areas set to benefit more from this new paradigm in clinical genetics than neurological disorders, particularly those affecting Selleck PFT�� children. There are several interconnected reasons for this: much of neurological illness has already been shown to have a genetic basis; it is often difficult to predict the genetic defect on clinical grounds; new causative variants are being described weekly; and it is expensive and burdensome to test on a gene-by-gene basis. In addition, the global burden of unexplained neurological disorders

is immense. Epilepsy alone affects 6o million people worldwide, and the diagnosis of epilepsy encompasses a large group of brain disorders characterized by the occurrence of recurrent unprovoked seizures; one third of these individuals have medically refractory, poorly controlled seizures. Although there may be a recognized proximate cause in an individual patient (e.g., traumatic brain injury), in about 50% of those check details with epilepsy, no known etiology is apparent. It is likely that a large proportion of these individuals have an underlying genetic underpinning to their epilepsy. Many may be due to individual mutations affecting a variety of proteins and pathways necessary for normal brain

development and function. Similarly, 1%–3% of the population has a lifelong intellectual disability (ID; from mild to profound) with associated significant long-term personal, family, social, and economic consequences. Again, the etiology of intellectual disability is unknown in about oxyclozanide half of individuals. Recent evidence confirms that, as with epilepsy, the underlying causes of ID are molecularly diverse, with a significant proportion accounted for by functionally deleterious de novo mutations across a spectrum of genes (de Ligt et al., 2012 and Rauch et al., 2012). Moreover, there is overlap between epilepsy and ID, whereby one third of individuals with ID have epilepsy as a manifestation of their underlying brain disorder, and approximately 20% of patients attending a tertiary referral epilepsy clinic have an associated intellectual disability. A recent study has shown that de novo mutations are important as a cause of previously unexplained childhood epileptic encephalopathies, conditions generally associated with severe epilepsy and intellectual disability (Allen et al., 2013).