Pediatric neurogenetic diseases account for significant morbidity and mortality, and include relatively common conditions like epilepsy and intellectual disability (mental retardation) as well as rarer diseases such as dystonia (painful, abnormal muscle contractions) and juvenile-onset parkinsonism. For more than 50% of suspected genetic pediatric neurologic disorders, a conclusive diagnosis is not able to be reached. This lack of knowledge limits current interventions to solely targeting symptoms. By studying highly genetically informative families, we propose to identify novel genetic causes of pediatric neurological disorders, and characterize their pathophysiology. In so doing, we will not only improve clinical diagnosis, but also design future studies that focus on developing targeted therapies.