Table 1

Summary of the previously described mutations in COIII together with our new case

AA exchangePositionReferenceClinical pictureOnset% HeteroplasmyRRFCOX activity
F251LT9957C missenseManfredi et al9MELAS6 years81% in muscle, 60% in bloodFewLow to normal
Missing 94–98 (FAGFF)15bp in frame deletionKeightley et al4Recurrent myoglobinuria15 years97% in muscle, 0.7% in bloodSeveral14% residual activity
W249XG9952AHanna et al5Myoglubinuria, myopathy, encephalopathy17 years57% in muscle, 0% in bloodNo20% residual activity
Q111X9537 insCTiranti et al10Leigh-like syndrome4 yearsVirtually homoplasmic (muscle, fibroblasts, blood)No10% residual activity
W58XG9379AThis paperMyopathy6 years93% in muscle, 0% in bloodNumerous9% residual activity