NM_002693.3:c.3176A>G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PP3_Strong

The NM_002693.3(POLG):c.3176A>G(p.Asn1059Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000973 in 1,614,034 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000085 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000099 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:11

Conservation

PhyloP100: 7.49

Variant links:

Genes affected

POLG (HGNC:9179): (DNA polymerase gamma, catalytic subunit) Mitochondrial DNA polymerase is heterotrimeric, consisting of a homodimer of accessory subunits plus a catalytic subunit. The protein encoded by this gene is the catalytic subunit of mitochondrial DNA polymerase. The encoded protein contains a polyglutamine tract near its N-terminus that may be polymorphic. Defects in this gene are a cause of progressive external ophthalmoplegia with mitochondrial DNA deletions 1 (PEOA1), sensory ataxic neuropathy dysarthria and ophthalmoparesis (SANDO), Alpers-Huttenlocher syndrome (AHS), and mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE). Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]

POLG links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.972

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3 link	c.3176A>G	p.Asn1059Ser	missense_variant	Exon 20 of 23	ENST00000268124.11	NP_002684.1	P54098E5KNU5
POLG	NM_001126131.2 link	c.3176A>G	p.Asn1059Ser	missense_variant	Exon 20 of 23		NP_001119603.1	P54098E5KNU5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11 link	c.3176A>G	p.Asn1059Ser	missense_variant	Exon 20 of 23	1	NM_002693.3	ENSP00000268124.5		P54098

Frequencies

GnomAD3 genomes

AF:

0.0000854

AC:

AN:

152162

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000882

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000876

AC:

AN:

251116

Hom.:

AF XY:

0.000110

AC XY:

AN XY:

135752

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.0000868

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.000229

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000705

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000985

AC:

144

AN:

1461872

Hom.:

Cov.:

AF XY:

0.0000990

AC XY:

AN XY:

727232

show subpopulations

Gnomad4 AFR exome

AF:

0.000179

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.000220

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000980

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.0000854

AC:

AN:

152162

Hom.:

Cov.:

AF XY:

0.0000942

AC XY:

AN XY:

74332

show subpopulations

Gnomad4 AFR

AF:

0.000145

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000882

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000831

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000132

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000178

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:11

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:5

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Jun 26, 2014

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 20, 2021

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported previously in the heterozygous state in a patient with epilepsy (Need et al., 2012); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 22863191) -

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Dec 17, 2022

Al Jalila Children’s Genomics Center, Al Jalila Childrens Speciality Hospital

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Uncertain:2

Mar 12, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: POLG c.3176A>G (p.Asn1059Ser) results in a conservative amino acid change located in the DNA-directed DNA polymerase, family A, palm domain (IPR001098) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8.8e-05 in 251116 control chromosomes. c.3176A>G has been reported in the literature in individuals affected with early-onset Parkinsons disease and Status Epilepticus, without strong evidence for causality (Chen_2022, Naofal_2023, Zhao_2020). These report(s) do not provide unequivocal conclusions about association of the variant with POLG-Related Spectrum Disorders. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 35861376, 36703223, 32613234). ClinVar contains an entry for this variant (Variation ID: 195487). Based on the evidence outlined above, the variant was classified as uncertain significance. -

May 04, 2017

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Progressive sclerosing poliodystrophy;C1834846:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1;C1843851:Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis;C3150914:Mitochondrial DNA depletion syndrome 4b;C4225153:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 1;C4551995:Mitochondrial DNA depletion syndrome 1

Uncertain:1

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

POLG-Related Spectrum Disorders

Uncertain:1

Apr 27, 2017

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

POLG-related disorder

Uncertain:1

Aug 30, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The POLG c.3176A>G variant is predicted to result in the amino acid substitution p.Asn1059Ser. This variant was reported in the heterozygous state in an individual with early onset Parkinson disease (Table S4B, Zhao et al. 2020. PubMed ID: 32613234; Table S12.1, Chen et al. 2022. PubMed ID: 35861376) and in a patient with epilepsy (Table S10, El Naofal et al. 2023. PubMed ID: 36703223). This variant is reported in 0.023% of alleles in individuals of South Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Progressive sclerosing poliodystrophy

Uncertain:1

Nov 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 1059 of the POLG protein (p.Asn1059Ser). This variant is present in population databases (rs201192905, gnomAD 0.02%). This missense change has been observed in individual(s) with POLG-related conditions (PMID: 32613234, 35861376, 36703223). ClinVar contains an entry for this variant (Variation ID: 195487). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt POLG protein function with a positive predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.41

BayesDel_addAF

Uncertain

0.015

BayesDel_noAF

Uncertain

0.080

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.95

D;D

Eigen

Pathogenic

0.90

Eigen_PC

Pathogenic

0.83

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Pathogenic

1.0

.;D

M_CAP

Pathogenic

0.47

MetaRNN

Pathogenic

0.97

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.5

M;M

PrimateAI

Benign

0.45

PROVEAN

Pathogenic

-4.7

D;D

REVEL

Pathogenic

0.93

Sift

Uncertain

0.0040

D;D

Sift4G

Uncertain

0.0070

D;D

Polyphen

1.0

D;D

Vest4

0.89

MVP

0.99

MPC

0.58

ClinPred

0.78

GERP RS

5.3

Varity_R

0.67

gMVP

0.77

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over