Among these diseases, MEOAL is an inherited neuromuscular disorder caused by homozygous mutations of FDX2. To date only 11 patients have been reported presenting clinical phenotypes with variable onset and severity, ranging from muscle weakness and exercise intolerance with episodic exacerbation to a more complex neurological involvement which may include optic atrophy, reversible or partially reversible leukoencephalopathy and later onset of a sensory-motor polyneuropathy [1–6]. Here, FDX2 is linked to hereditary optic atrophy.