Rita Horvath & Patrick F. Chinnery
Genetic diagnostics have undergone a revolution in the last decade, fueled by technological advances heralded by the development of massively parallel DNA sequencing. Within a remarkably short time, the new chemistry moved from the research laboratory into clinical practice, accelerating the pace of gene discovery and allowing the rapid diagnosis of genetic disorders on an unprecedented scale. There is a strong argument that so-called next or third generation sequencing will have the greatest effect in neurology, which is characterized by a seemingly endless list of discrete clinical syndromes, many thought to have a unique genetic basis. Until 2011, clinical neurogenetic practice has been frustrating. It has been difficult to screen more than a handful of the known genetic causes of a particular disorder, but we now face the real prospect of a reaching genetic diagnosis for every patient walking to the clinical door. Mitochondrial disorders provide a good illustration of the effect of this new technology in neurogenetic practice.