Progressive myoclonus epilepsy strikes healthy children and has a slow yet devastating impact upon their lives. Almost all forms are caused by single gene defects, the majority of which were identified during the genomic era. Accurate clinical diagnosis is now straightforward and research into pathogenesis builds upon our understanding of causation. Future research is likely to lead to new therapeutic approaches while providing us with a better understanding of how the brain, the very essence of our being, operates, gene by gene. As we stand on the cusp of the post-genomic era, the emergence of unprecedented new tools, such as CRISPR and adeno-associated viruses, offers hope that these monogenetic diseases may one day be eliminated altogether. This book outlines the genetic, pathogenetic, pathological, and clinical aspects of progressive myoclonus epilepsies within the context of the post-genomic era.