There is conflicting evidence for the association between this repeat expansion and Parkinson's risk^4,6,7, as well as overall disease significance. May be predisposing factor in earlier age of onset in FRDA patients⁸. This locus's relevance to CPEO specifically is disputed: the cited sources evaluate the POLG CAG repeat primarily as a modifier/association signal in Parkinson's disease and Friedreich ataxia cohorts rather than in CPEO patients directly⁷; pathogenic POLG coding variants, which are distinct from this repeat, are a separately well-established cause of CPEO. See the criTRia curation for full evidence details⁹.

Mechanism

Detection

Year

–

Location in Gene

Coding Exon 2

Gene Strand

Alleles

Ref. Motif

CTG

Ranges

Benign (ref.)

–

Benign (gene)

–

Pathogenic (ref.)

CTG

Pathogen. (gene)

CAG

Unknown (ref.)

–

Unknown (gene)

–

Interruption (ref.)

–

Interrup. (gene)

–

References

Direct supporting references for info on this page.

Neurological disorders caused by novel non-coding repeat expansions: clinical features and differential diagnosis.

Elisa,Vegezzi, Hiroyuki,Ishiura, D Cristopher,Bragg, David,Pellerin, Francesca,Magrinelli, Riccardo,Currò, Stefano,Facchini, Arianna,Tucci, John,Hardy, Nutan,Sharma, Matt C,Danzi, Stephan,Zuchner, Bernard,Brais, Mary M,Reilly, Shoji,Tsuji, Henry,Houlden, Andrea,Cortese

The Lancet. Neurology · 2024-07-01

pmid:38876750

2omim:258450

3omim:157640

POLG1 polyglutamine tract variants associated with Parkinson's disease.

Johanna,Eerola, Petri T,Luoma, Terhi,Peuralinna, Sonja,Scholz, Coro,Paisan-Ruiz, Anu,Suomalainen, Andrew B,Singleton, Pentti J,Tienari

Neuroscience letters · 2010-04-24

pmid:20399836

Variations of the CAG trinucleotide repeat in DNA polymerase γ (POLG1) is associated with Parkinson's disease in Sweden.

Anna,Anvret, Marie,Westerlund, Olof,Sydow, Thomas,Willows, Charlotta,Lind, Dagmar,Galter, Andrea Carmine,Belin

Neuroscience letters · 2010-09-06

pmid:20826197

Analysis of the trinucleotide CAG repeat from the human mitochondrial DNA polymerase gene in healthy and diseased individuals.

A,Rovio, V,Tiranti, A L,Bednarz, A,Suomalainen, J N,Spelbrink, N,Lecrenier, A,Melberg, M,Zeviani, J,Poulton, F,Foury, H T,Jacobs

European journal of human genetics : EJHG · 1999-01-01

pmid:10196696

Number of CAG repeats in POLG1 and its association with Parkinson disease in the Norwegian population.

Novin,Balafkan, Charalampos,Tzoulis, Bernd,Müller, Kristoffer,Haugarvoll, Ole-Bjørn,Tysnes, Jan Petter,Larsen, Laurence A,Bindoff

Mitochondrion · 2012-08-29

pmid:22963882

Association between trinucleotide CAG repeats of the DNA polymerase gene (POLG) with age of onset of Iranian Friedreich's ataxia patients.

Mohammad Mehdi,Heidari, Massoud,Houshmand, Saman,Hosseinkhani, Shahriar,Nafissi, Barbara,Scheiber-Mojdehkar, Mehri,Khatami

Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2008-11-28

pmid:19043662

STRchive

url:https://strchive.org/critria/CPEO_POLG

Additional Literature

Additional literature related to this locus.

Raw PubMed search results
(All PubMed results returned by searching for this gene, tandem repeats, and disease, in medline format)

Repeat Variants, Biomarkers, and Molecular Signatures in Parkinson's Disease:

Jose Miguel,Laffita-Mesa, Martin,Paucar, Per,Svenningsson

International journal of molecular sciences · 2025-09-20

pmid:41009775

Whole genome sequencing analysis in primary lateral sclerosis (PLS) patients reveals mutations in neurological diseases-causing genes.

Arianna,Manini, Alberto,Brusati, Maurizio,Grassano, Giulia,Scacciatella, Silvia,Peverelli, Jacopo,Spagliardi, Viviana,Pensato, Alberto,Doretti, Rosario,Vasta, Umberto,Manera, Antonio,Canosa, Maura,Brunetti, Davide,Gentilini, Stefano,Messina, Federico,Verde, Cristina,Moglia, Claudia,Morelli, Eleonora,Dalla Bella, Pamela J,Keagle, John E,Landers, Cinzia,Gellera, Giuseppe,Lauria Pinter, Adriano,Chiò, Antonia,Ratti, Andrea,Calvo, Vincenzo,Silani, Nicola,Ticozzi

Journal of neurology · 2025-08-22

pmid:40844737

Diagnosis of hereditary ataxias: a real-world single center experience.

Adriana,Meli, Vincenzo,Montano, Giovanni,Palermo, Antonella,Fogli, Anna,Rocchi, Annalisa Lo,Gerfo, Rossella,Maltomini, Ludovica,Cori, Antonio,Siniscalchi, Clara,Bernardini, Giulia,Cecchi, Gabriele,Siciliano, Roberto,Ceravolo, Maria Adelaide,Caligo, Michelangelo,Mancuso, Piervito,Lopriore

Journal of neurology · 2025-01-15

pmid:39812846

Molecular epidemiology of hereditary ataxia in Finland.

Joonas,Lipponen, Seppo,Helisalmi, Joose,Raivo, Ari,Siitonen, Hiroshi,Doi, Harri,Rusanen, Maria,Lehtilahti, Mervi,Ryytty, Markku,Laakso, Fumiaki,Tanaka, Kari,Majamaa, Laura,Kytövuori

BMC neurology · 2021-10-02

pmid:34600502

Genetic risk factors in Finnish patients with Parkinson's disease.

Susanna,Ylönen, Ari,Siitonen, Michael A,Nalls, Pauli,Ylikotila, Jaana,Autere, Johanna,Eerola-Rautio, Raphael,Gibbs, Mikko,Hiltunen, Pentti J,Tienari, Hilkka,Soininen, Andrew B,Singleton, Kari,Majamaa

Parkinsonism & related disorders · 2017-09-29

pmid:29029963

A panel study on patients with dominant cerebellar ataxia highlights the frequency of channelopathies.

Marie,Coutelier, Giulia,Coarelli, Marie-Lorraine,Monin, Juliette,Konop, Claire-Sophie,Davoine, Christelle,Tesson, Rémi,Valter, Mathieu,Anheim, Anthony,Behin, Giovanni,Castelnovo, Perrine,Charles, Albert,David, Claire,Ewenczyk, Mélanie,Fradin, Cyril,Goizet, Didier,Hannequin, Pierre,Labauge, Florence,Riant, Pierre,Sarda, Yves,Sznajer, François,Tison, Urielle,Ullmann, Lionel,Van Maldergem, Fanny,Mochel, Alexis,Brice, Giovanni,Stevanin, Alexandra,Durr

Brain : a journal of neurology · 2017-06-01

pmid:28444220

The POLG Polyglutamine Tract Variants in Iranian Patients with Multiple Sclerosis.

Mehri,Khatami, Mohammad Mehdi,Heidari, Reza,Mansouri, Fatemeh,Mousavi

Iranian journal of child neurology · 2015-01-01

pmid:25767537

Rare POLG1 CAG variants do not influence Parkinson's disease or polymerase gamma function.

Steven R,Bentley, Jianguo,Shan, Michael,Todorovic, Stephen A,Wood, George D,Mellick

Mitochondrion · 2014-01-31

pmid:24491464

Mitochondrial DNA polymerase gamma gene polymorphism is not associated with male infertility.

J,Poongothai

Journal of assisted reproduction and genetics · 2013-08-04

pmid:23912752

Locus CPEO POLG

Disease

Locus

Alleles

References

Additional Literature