Erratum to: The presence of anaemia negatively influences survival in patients with POLG disease. Issue 1 (26th September 2017) - Hikmat, Omar; Tzoulis, Charalampos; Klingenberg, Claus; Rasmussen, Magnhild; Tallaksen, Chantal M. E.; Brodtkorb, Eylert; Fiskerstrand, Torunn; McFarland, Robert; Rahman, Shamima; Bindoff, Laurence A.