Evidence map›Paper›PMID 41220167›Full record

ArticleBrain and behavior2025

Characterization of Novel POLG Mutations in Mitochondrial Encephalomyopathy: Pathogenic Validation and Comprehensive Genetic Profiling.

Fanjing Zhou, Jiang Chen, Tingzheng Zhang, Fengnan Niu, Jinglong Hu, Yun Xu, Meijuan Zhang

Abstract readCase Reports
In one paragraph

Article in Brain and behavior, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

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2citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Multi-ancestry analysis ofmedRxiv : the preprint server for health sciences · 2026
    Article
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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Fanjing ZhouDepartment of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.ORCID https://orcid.org/0009-0003-4367-1648
Jiang ChenDepartment of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
Tingzheng ZhangDepartment of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
Fengnan NiuDepartment of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
Jinglong HuDepartment of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
Yun XuDepartment of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.
Meijuan ZhangDepartment of Neurology, Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, Nanjing, China.

Funding

National Key Research and Development Program of China 2023ZD0505200National Natural Science Foundation of China 81920108017National Natural Science Foundation of China 82071408National Natural Science Foundation of China 82471352Natural Science Foundation of Jiangsu Province BK20191116
6 · The paper itself

Abstract

INTRODUCTION/

aimsMitochondrial encephalomyopathies are multisystem disorders caused by defects in mitochondrial DNA (mtDNA) or nuclear DNA (nDNA). Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis (SANDO) syndrome is a rare manifestation, often associated with POLG mutations. This study identifies a novel POLG mutation in a SANDO patient, validates its pathogenicity, and analyzes the molecular genetics of 61 reported POLG-SANDO cases.

methodsAfter obtaining informed consent, the proband underwent neurological examination, electromyography, muscle/nerve biopsies (histochemical/ultrastructural analyses), and genetic testing (whole-exome sequencing, mtDNA analysis). Pathogenicity of identified POLG variants was assessed in Cas9-mediated primary neuronal models expressing mutant proteins by measuring reactive oxygen species (ROS) levels and mtDNA copy number (qRT-PCR, ND1/APP ratio). Literature searches (PubMed, CNKI, Wanfang, and ClinVar) identified reported POLG mutations and clinical features in SANDO.

resultsClinical and biopsy findings confirmed SANDO syndrome. Genetic analysis revealed compound heterozygous POLG mutations: a novel c.3297G>C (p.W1099C) and a known c.1774C>T (p.L592F). Neurons expressing either mutant exhibited elevated ROS levels (p < 0.05) and reduced mtDNA copy number compared with controls. Literature synthesis identified over 30 SANDO-associated POLG mutations, with p.A467T (31.2%) and p.W748S (22.1%) being the most frequent. The mean age of onset was 31.6 years.

conclusionsWe identify a novel pathogenic POLG variant (p.W1099C) causing mitochondrial dysfunction via impaired mtDNA maintenance, expanding the SANDO genetic spectrum. Functional studies confirmed both mutations induce mitochondrial dysfunction (elevated ROS and decreased mtDNA Copy Number), validating their pathogenicity. The compiled mutation profile aids diagnosis of this phenotypically heterogeneous, frequently misdiagnosed disorder.

Indexed as

DNA Polymerase gammaMitochondrial EncephalomyopathiesAdultAnimalsDNA, MitochondrialFemaleHumansMaleMiceMutationDNA, MitochondrialDNA Polymerase gammaPOLG protein, humanmitochondrial encephalomyopathyPOLG mutationSANDO

Identifiers

PMID41220167
PMCPMC12605960

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