Leigh syndrome represents one of the most common pediatric-onset mitochondrial diseases. It can occur due to mitochondrial DNA encoded or nuclear DNA encoded mutations. Children generally present with symtoms from infancy or a regression in functioning after a period of typical development. Symptoms are predominantly due to basal ganglia, brainstem or cerebellar dysfunction. The disease is progressive over months to years.
Parikh, S. (2015). Leigh Syndrome. In Mitochondrial Case Studies: Underlying Mechanisms and Diagnosis (pp. 65–68). Elsevier Inc. https://doi.org/10.1016/B978-0-12-800877-5.00008-5