15-89317458-C-G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got -3 ACMG points: 2P and 5B. BP7PM2BS2

This summary comes from the ClinGen Evidence Repository: The c.3561 G>C (p.Arg1187=) variant in POLG is present in population databases 1000 genome 0.03%, ExAC at 0.002%, and gnomAD at 0.002% (PM2; observed < 0.05% frequency). Computational prediction tool Revel unavailable given limited data. This variant was observed in homozygotes in 13 cases in gnomAD and 1 case in ExAC (BS2). This variant is a coding synonymous change (BP7). In summary, there is not sufficient evidence to characterize this variant as pathogenic or benign, therefore it is characterized as a variant of uncertain significance for primary mitochondrial disease inherited in a autosomal recessive manner.ntDNA Mitochondrial ACMG-AMP Criteria for POLG applied: BS2, PM2, BP7. LINK:https://erepo.genome.network/evrepo/ui/classification/CA288989/MONDO:0044970/014

Frequency

Genomes: 𝑓 0.0073 ( 16 hom., cov: 32)

Exomes 𝑓: 0.00073 ( 15 hom. )

Consequence

POLG
NM_002693.3 synonymous

Scores

Clinical Significance

Uncertain significance reviewed by expert panel U:1B:9

Conservation

PhyloP100: 1.22

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:

FANCI (HGNC:25568): (FA complementation group I) The Fanconi anemia complementation group (FANC) currently includes FANCA, FANCB, FANCC, FANCD1 (also called BRCA2), FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ (also called BRIP1), FANCL, FANCM and FANCN (also called PALB2). The previously defined group FANCH is the same as FANCA. Fanconi anemia is a genetically heterogeneous recessive disorder characterized by cytogenetic instability, hypersensitivity to DNA crosslinking agents, increased chromosomal breakage, and defective DNA repair. The members of the Fanconi anemia complementation group do not share sequence similarity; they are related by their assembly into a common nuclear protein complex. This gene encodes the protein for complementation group I. Alternative splicing results in two transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

FANCI links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got -3 ACMG points.

PM2

For more information check the summary or visit ClinGen Evidence Repository.

BP7

For more information check the summary or visit ClinGen Evidence Repository.

BS2

For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3 link	c.3561G>C	p.Arg1187Arg	synonymous_variant	Exon 22 of 23	ENST00000268124.11	NP_002684.1	P54098E5KNU5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11 link	c.3561G>C	p.Arg1187Arg	synonymous_variant	Exon 22 of 23	1	NM_002693.3	ENSP00000268124.5		P54098

Frequencies

GnomAD3 genomes

AF:

0.00726

AC:

1105

AN:

152148

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0255

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00242

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:

0.0000294

Gnomad OTH

AF:

0.00526

GnomAD3 exomes

AF:

0.00177

AC:

445

AN:

251490

Hom.:

AF XY:

0.00121

AC XY:

165

AN XY:

135918

show subpopulations

Gnomad AFR exome

AF:

0.0251

Gnomad AMR exome

AF:

0.000838

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000489

GnomAD4 exome

AF:

0.000727

AC:

1063

AN:

1461778

Hom.:

Cov.:

AF XY:

0.000619

AC XY:

450

AN XY:

727194

show subpopulations

Gnomad4 AFR exome

AF:

0.0275

Gnomad4 AMR exome

AF:

0.00110

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000232

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.00136

GnomAD4 genome

AF:

0.00728

AC:

1108

AN:

152266

Hom.:

Cov.:

AF XY:

0.00732

AC XY:

545

AN XY:

74468

show subpopulations

Gnomad4 AFR

AF:

0.0255

Gnomad4 AMR

AF:

0.00242

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00521

Alfa

AF:

0.00221

Hom.:

Bravo

AF:

0.00828

Asia WGS

AF:

0.00115

AC:

AN:

3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1Benign:9

Revision: reviewed by expert panel

LINK: link

Submissions by phenotype

not specified

Benign:3

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 22, 2013

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Genetic Services Laboratory, University of Chicago

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

Likely benign based on allele frequency in 1000 Genomes Project or ESP global frequency and its presence in a patient with a rare or unrelated disease phenotype. NOT Sanger confirmed. -

Progressive sclerosing poliodystrophy

Benign:3

Jan 30, 2024

Mendelics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 01, 2018

Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NM_002693.2:c.3561G>C (NP_002684.1:p.Arg1187=) [GRCH38: NC_000015.10:g.89317458C>G] variant in POLG gene is interpretated to be a Benign based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. BS1:The minor allele frequency of this allele is high for Mitochondrial DNA depletion syndrome 4A (Alpers type). BS2:Observation of the variant in controls is inconsistent with penetrance of Mitochondrial DNA depletion syndrome 4A (Alpers type). BP4:Computational evidence/predictors indicate no impact on the POLG structure, function, or protein-protein interaction. BP7:The variant is silent with non predicted splice impact. Based on the evidence criteria codes applied, the variant is suggested to be Benign. -

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mitochondrial disease

Uncertain:1

May 06, 2021

ClinGen Mitochondrial Disease Nuclear and Mitochondrial Variant Curation Expert Panel, ClinGen

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

The c.3561 G>C (p.Arg1187=) variant in POLG is present in population databases 1000 genome 0.03%, ExAC at 0.002%, and gnomAD at 0.002% (PM2; observed < 0.05% frequency). Computational prediction tool Revel unavailable given limited data. This variant was observed in homozygotes in 13 cases in gnomAD and 1 case in ExAC (BS2). This variant is a coding synonymous change (BP7). In summary, there is not sufficient evidence to characterize this variant as pathogenic or benign, therefore it is characterized as a variant of uncertain significance for primary mitochondrial disease inherited in a autosomal recessive manner. ntDNA Mitochondrial ACMG-AMP Criteria for POLG applied: BS2, PM2, BP7. -

POLG-Related Spectrum Disorders

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Inborn genetic diseases

Benign:1

Jul 28, 2016

Ambry Genetics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

not provided

Benign:1

May 21, 2019

Athena Diagnostics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.40

CADD

Benign

6.5

DANN

Benign

0.81

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