CPEO_POLG

Gene
POLG
Disease
CPEO
Inheritance
Classification
Disputed
Total Score
7
Publications Reviewed
1
Publication Span
Last Updated
08/18/2025
Curator(s)
Macayla Weiner, Laurel Hiatt

Description

The curated POLG CAG/polyglutamine repeat has disputed relevance to CPEO. The provided sources evaluate the repeat primarily as a modifier/association signal in Parkinson disease and Friedreich ataxia, and note that pathogenic POLG coding variants can cause progressive external ophthalmoplegia; they do not provide direct evidence that POLG CAG-repeat variation causes CPEO.

Genetic evidence

Total: 6

Singular EvidenceProbandsPMID:229638826Reports 191 Parkinson disease cases and 191 controls sequenced for the POLG1 CAG repeat; it does not describe CPEO probands.
1 rows

Experimental evidence

Total: 1

FunctionBiochemical functionPMID:229638820.5Gene-level evidence: POLG encodes the catalytic subunit of mitochondrial DNA polymerase gamma, which replicates and repairs mtDNA; PMID 22963882 does not provide a CPEO-specific functional assay of the CAG repeat.
FunctionProtein interactionPMID:229638820.5Gene-level evidence: polymerase gamma is described as a heterotrimer comprising one POLG1 catalytic subunit and two POLG2 accessory subunits; no CAG-repeat- or CPEO-specific altered interaction is shown.
2 rows

Note: Maximum score caps apply at evidence type, category, and supercategory levels, so section totals may be lower than the raw sum of row scores.