Epilepsy Genetics.

Objective: This article reviews essential concepts and terminology in epilepsy genetics, discusses current guidance on when and how to pursue genetic evaluation, provides an overview of genetic syndromes, and offers illustrative examples of the effect of genetic diagnosis in epilepsy patient care.

Latest developments: The growing availability of next-generation genetic sequencing methods for clinical use provides an opportunity to make etiologic diagnoses in a larger number of epilepsy patients, which can affect therapeutic management, prognostic counseling, surveillance for comorbid conditions, and other aspects of epilepsy care. Exome and genome sequencing may have high diagnostic yields in patients with unexplained epilepsy. The body of knowledge in epilepsy genetics is growing more complex, not only because of gene discovery but also because of an increasingly nuanced understanding of the varying pathophysiologic effects of specific types of variation within epilepsy genes.

Essential points: Genetic testing plays a key role in the evaluation of epilepsy patients. Clinicians caring for patients with epilepsy should understand patient selection, test selection, and result interpretation in genetic testing. The recommended first-line test in most patients is exome or genome sequencing.