Fig. 11

Oculopharyngeal muscular dystrophy, oculopharyngodistal myopathy and mitochondrial disorders diagnostic diagram (Yamashita et al., 2021; Stevanovski et al. 2022; Kumutpongpanich et al. 2021; Ogasawara et al. 2020, 2022; Gorman et al. 2015; Gusic and Prokisch 2021). Molecular studies confirm oculopharyngeal muscular dystrophy and oculopharyngeal muscular dystrophy diagnosis, therefore muscle biopsy is usually not necessary. Muscle tissue may be necessary for genetic studies of the mitochondrial DNA to avoid false negative results in DNA extracted from blood. Muscle biopsy may confirm the phenotype of mitochondriopathy with abnormalities in respiratory chain studies, histochemical proof of dysfunction with ragged red fibres (RRF), cytochrome-c-oxidative negative or COX (-) fibres, and ultrastructural abnormalities of the mitochondriae. bp: base pairs; COX(-): cytochrome c oxidase negative fibres; DNA: deoxyribonucleic acid; EEG: electroencephalogram. EM: electron microscopy. FGF-21: fibroblast growth factor 21; GDF-15: growth differentiation factor 15; GIPC1: GIPC PDZ domain containing family member 1 gene; IPx: immunohistochemistry; KSS: Kearns-Sayre syndrome; LHON: Leber hereditary optic neuropathy; LRP12: Low-density lipoprotein receptor-related protein 12 gene; MELAS: Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes; MERRF: Myoclonic Epilepsy associated with Ragged-Red Fibres; MILS: maternally inherited Leigh Syndrome; mtDNA: mitochondrial deoxyribonucleic acid; NARP: neuropathy, ataxia, and retinitis pigmentosa; NOTCH2NLC: Notch homolog 2 N-terminal-like protein C gene; OPDM: oculopharyngodistal myopathy; OPMD: oculopharyngeal muscular dystrophy; PABPN1 gene (OPDM): polyadenilate-binding protein nuclear 1; POLG1 gene: polymerase, DNA, gamma-1 gene; RILPL1: PEO: progressive external ophthalmoplegia; Rab interacting lysosomal protein like 1 gene; yo: years old