Episodic mitochondrial myopathy with or without optic atrophy and reversible leukoencephalopathy (MEOAL) is a rare, orphan autosomal recessive disorder caused by mutations in ferredoxin‐2 (FDX2), which is a [2Fe‐2S] cluster‐binding protein participating in the formation of iron–sulfur clusters in mitochondria. The gene discussed is FDX2; the disease is Mitochondrial myopathy.