A study found that the levels of ROS radicals (superoxide anion (O2•−) and H2O2) along with malondialdehyde (MDA) and nitrotyrosine were higher in the LF from LSS patients, whereas the expression and level of antioxidant glutathione peroxidase (GPx-1), glutathione (GSH), and superoxide dismutase (SOD) activity were lower in the LF from LSS patients [14], suggesting a redox imbalance during HLF. This evidence concerns the gene SOD1 and Leigh syndrome.