NM_002693.3:c.948G>A

Variant names:

Variant summary

Our verdict is Benign. The variant received -19 ACMG points: 0P and 19B. BP4_ModerateBP6_Very_StrongBP7BS1BS2

The NM_002693.3(POLG):c.948G>A(p.Lys316Lys) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00209 in 1,613,456 control chromosomes in the GnomAD database, including 36 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0027 ( 8 hom., cov: 32)

Exomes 𝑓: 0.0020 ( 28 hom. )

Consequence

POLG
NM_002693.3 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:16

Conservation

PhyloP100: 1.81

Publications

6 publications found

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 Gene-Disease associations (from GenCC):

progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
mitochondrial DNA depletion syndrome 4a
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Orphanet, G2P
sensory ataxic neuropathy, dysarthria, and ophthalmoparesis
Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, G2P
autosomal dominant progressive external ophthalmoplegia
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
autosomal recessive progressive external ophthalmoplegia
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
mitochondrial neurogastrointestinal encephalomyopathy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
recessive mitochondrial ataxia syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
spinocerebellar ataxia with epilepsy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
Leigh syndrome
Inheritance: AR Classification: LIMITED Submitted by: ClinGen

POLG links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -19 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.36).

BP6

Variant 15-89329018-C-T is Benign according to our data. Variant chr15-89329018-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 129999.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=1.81 with no splicing effect.

BS1

Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.00272 (415/152346) while in subpopulation EAS AF = 0.0148 (77/5188). AF 95% confidence interval is 0.0122. There are 8 homozygotes in GnomAd4. There are 276 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

BS2

High Homozygotes in GnomAd4 at 8 AR,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3 link	c.948G>A	p.Lys316Lys	synonymous_variant	Exon 4 of 23	ENST00000268124.11	NP_002684.1	P54098E5KNU5
POLG	NM_001126131.2 link	c.948G>A	p.Lys316Lys	synonymous_variant	Exon 4 of 23		NP_001119603.1	P54098E5KNU5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11 link	c.948G>A	p.Lys316Lys	synonymous_variant	Exon 4 of 23	1	NM_002693.3	ENSP00000268124.5		P54098

Frequencies

GnomAD3 genomes

AF:

0.00273

AC:

416

AN:

152228

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00150

Gnomad ASJ

AF:

0.000576

Gnomad EAS

AF:

0.0148

Gnomad SAS

AF:

0.00434

Gnomad FIN

AF:

0.0232

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000573

Gnomad OTH

AF:

0.00191

GnomAD2 exomes

AF:

0.00421

AC:

1050

AN:

249356

AF XY:

0.00426

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000492

Gnomad ASJ exome

AF:

0.00120

Gnomad EAS exome

AF:

0.0138

Gnomad FIN exome

AF:

0.0240

Gnomad NFE exome

AF:

0.000724

Gnomad OTH exome

AF:

0.00311

GnomAD4 exome

AF:

0.00203

AC:

2963

AN:

1461110

Hom.:

Cov.:

AF XY:

0.00215

AC XY:

1563

AN XY:

726830

show subpopulations

African (AFR)

AF:

0.000329

AC:

AN:

33464

American (AMR)

AF:

0.000514

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00122

AC:

AN:

26136

East Asian (EAS)

AF:

0.0144

AC:

572

AN:

39700

South Asian (SAS)

AF:

0.00535

AC:

461

AN:

86220

European-Finnish (FIN)

AF:

0.0240

AC:

1277

AN:

53268

Middle Eastern (MID)

AF:

0.0125

AC:

AN:

5272

European-Non Finnish (NFE)

AF:

0.000341

AC:

379

AN:

1112004

Other (OTH)

AF:

0.00235

AC:

142

AN:

60322

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.483

Heterozygous variant carriers

208

415

623

830

1038

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

120

150

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00272

AC:

415

AN:

152346

Hom.:

Cov.:

AF XY:

0.00371

AC XY:

276

AN XY:

74490

show subpopulations

African (AFR)

AF:

0.0000721

AC:

AN:

41584

American (AMR)

AF:

0.00150

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.000576

AC:

AN:

3472

East Asian (EAS)

AF:

0.0148

AC:

AN:

5188

South Asian (SAS)

AF:

0.00435

AC:

AN:

4830

European-Finnish (FIN)

AF:

0.0232

AC:

246

AN:

10612

Middle Eastern (MID)

AF:

0.00340

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000573

AC:

AN:

68034

Other (OTH)

AF:

0.00142

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.503

Heterozygous variant carriers

100

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000677

Hom.:

Bravo

AF:

0.00119

Asia WGS

AF:

0.00577

AC:

AN:

3478

EpiCase

AF:

0.000545

EpiControl

AF:

0.00101

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:16

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:6

Dec 14, 2023

Athena Diagnostics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 04, 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. -

Jun 17, 2015

Eurofins Ntd Llc (ga)

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mar 28, 2016

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: High allele frequency -

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

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

not provided

Benign:5

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Jan 11, 2017

Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Apr 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

POLG: BP4, BP7, BS1 -

Breakthrough Genomics, Breakthrough Genomics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:not provided

- -

Progressive sclerosing poliodystrophy

Benign:2

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.948G>A (NP_002684.1:p.Lys316=) [GRCH38: NC_000015.10:g.89329018C>T] 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). Based on the evidence criteria codes applied, the variant is suggested to be Benign. -

Jan 25, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

POLG-Related Spectrum Disorders

Benign:1

Jan 12, 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

Jun 23, 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. -

Hereditary spastic paraplegia

Benign:1

Feb 01, 2018

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance:Likely 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

-0.36

CADD

Benign

8.7

(source)

DANN

Benign

0.66

PhyloP100

1.8

PromoterAI

0.039

Neutral

(source)

Mutation Taster

=100/0

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over