{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T07:57:56Z","timestamp":1780387076357,"version":"3.54.1"},"reference-count":40,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2020,12,31]],"date-time":"2020-12-31T00:00:00Z","timestamp":1609372800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genes"],"abstract":"<jats:p>Mitochondrial encephalomyopathies comprise a group of heterogeneous disorders resulting from impaired oxidative phosphorylation (OxPhos). Among a variety of symptoms progressive external ophthalmoplegia (PEO) seems to be the most common. The aim of this study is to present clinical and genetic characteristics of Polish patients with PEO. Clinical, electrophysiological, neuroradiological, and morphological data of 84 patients were analyzed. Genetic studies of mitochondrial DNA (mtDNA) were performed in all patients. Among nuclear DNA (nDNA) genes POLG was sequenced in 41 patients, TWNK (C10orf2) in 13 patients, and RNASEH1 in 2 patients. Total of 27 patients were included in the chronic progressive external ophthalmoplegia (CPEO) group, 24 in the CPEO+ group. Twenty-six patients had mitochondrial encephalomyopathy (ME), six patients Kearns\u2013Sayre syndrome (KSS), and one patient sensory ataxic neuropathy, dysarthria, ophthalmoparesis (SANDO) syndrome. Genetic analysis of nDNA genes revealed the presence of pathogenic or possibly pathogenic variants in the POLG gene in nine patients, the TWNK gene in five patients and the RNASEH1 gene in two patients. Detailed patients\u2019 history and careful assessment of family history are essential in the diagnostic work-up. Genetic studies of both mtDNA and nDNA are necessary for the final diagnosis of progressive external ophthalmoplegia and for genetic counseling.<\/jats:p>","DOI":"10.3390\/genes12010054","type":"journal-article","created":{"date-parts":[[2020,12,31]],"date-time":"2020-12-31T10:10:37Z","timestamp":1609409437000},"page":"54","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Progressive External Ophthalmoplegia in Polish Patients\u2014From Clinical Evaluation to Genetic Confirmation"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8072-2497","authenticated-orcid":false,"given":"Biruta","family":"Kierdaszuk","sequence":"first","affiliation":[{"name":"Department of Neurology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3649-4375","authenticated-orcid":false,"given":"Magdalena","family":"Kaliszewska","sequence":"additional","affiliation":[{"name":"Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joanna","family":"Rusecka","sequence":"additional","affiliation":[{"name":"Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joanna","family":"Kosi\u0144ska","sequence":"additional","affiliation":[{"name":"Department of Medical Genetics, Medical University of Warsaw, Pawinskiego 3c, 02-106 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0489-7102","authenticated-orcid":false,"given":"Ewa","family":"Bartnik","sequence":"additional","affiliation":[{"name":"Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katarzyna","family":"To\u0144ska","sequence":"additional","affiliation":[{"name":"Institute of Genetics and Biotechnology, Faculty of Biology, University of Warsaw, Pawinskiego 5a, 02-106 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna M.","family":"Kami\u0144ska","sequence":"additional","affiliation":[{"name":"Department of Neurology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Kostera-Pruszczyk","sequence":"additional","affiliation":[{"name":"Department of Neurology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,12,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.mito.2014.10.005","article-title":"Tissue-specific mtDNA abundance from exome data and its correlation with mitochondrial transcription, mass and respiratory activity","volume":"20","author":"Atlante","year":"2015","journal-title":"Mitochondrion"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/0014-4827(91)90467-9","article-title":"Organization of multiple nucleoids and DNA molecules in mitochondria of a human cell","volume":"196","author":"Satoh","year":"1991","journal-title":"Exp. 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