A milestone in the treatment of Leigh syndrome, a rare, early-onset disease in children, has been reached: At the Hamburg site of the Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, in collaboration with Heinrich Heine University Düsseldorf (HHU) and University Hospital Düsseldorf (UKD), as well as Charité – Universitätsmedizin Berlin, a promising agent for the treatment of Leigh syndrome was identified. The researchers were able to demonstrate a positive effect of the active substance sildenafil on the disease course.