Mitochondrial complex IV deficiency caused by a novel frameshift variant in MT-CO2 associated with myopathy and perturbed acylcarnitine profile

摘要

Morphological features of the vastus lateralis muscle from the patient. Muscle architecture is relatively normal (Hematoxylin & Eosin). Cytochrome c oxidase (COX) enzyme histochemistry shows profound deficiency in the majority of the fibers. COX/succinate dehydrogenase (SDH)-double staining shows only scattered muscle fibers with normal COX activity. SDH enzyme histochemistry demonstrates mitochondrial proliferation. Several fibers with mitochondrial proliferation may be classified as ragged-red fibers (Gomori trichrome). Vacuoles containing lipid deposits are observed in many fibers (Sudan black). and On electron microscopy, the accumulation of mitochondria is clearly seen and they show slightly abnormal size and shape. Scale bar – , 20 μm