rs1056580076

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_002693.3(POLG):c.431A>G(p.Gln144Arg) variant causes a missense change. The variant allele was found at a frequency of 0.00000577 in 1,559,106 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q144E) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)

Exomes 𝑓: 0.0000050 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 5.92

Publications

1 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 links:

POLGARF (HGNC:56246): (POLG alternative reading frame) This gene uses the same transcript as the POLG gene but has a CUG start codon and an alternate reading frame that makes a 260 aa protein. This protein is distinct from POLG isoforms and may interact with P32 (also known as C1QBP), a mitochondrial matrix protein thought to be involved in the expression of mitochondrial genome-encoded proteins. POLGARF protein may bind P32 and sequester it in the nucleolus. Interestingly, some disease-causing mutations thought to be in POLG may instead be associated with POLGARF. [provided by RefSeq, May 2022]

POLGARF links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 20 uncertain in NM_002693.3

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3 link	c.431A>G	p.Gln144Arg	missense_variant	Exon 2 of 23	ENST00000268124.11	NP_002684.1	P54098E5KNU5
POLG	NM_001126131.2 link	c.431A>G	p.Gln144Arg	missense_variant	Exon 2 of 23		NP_001119603.1	P54098E5KNU5
POLGARF	NM_001430120.1 link	c.486A>G	p.Pro162Pro	synonymous_variant	Exon 1 of 2		NP_001417049.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11 link	c.431A>G	p.Gln144Arg	missense_variant	Exon 2 of 23	1	NM_002693.3	ENSP00000268124.5		P54098
POLGARF	ENST00000706918.1 link	c.486A>G	p.Pro162Pro	synonymous_variant	Exon 1 of 2			ENSP00000516626.1		A0A3B3IS91

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152224

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000118

AC:

AN:

169380

AF XY:

0.0000109

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000292

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000498

AC:

AN:

1406882

Hom.:

Cov.:

AF XY:

0.00000432

AC XY:

AN XY:

695084

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32044

American (AMR)

AF:

0.00

AC:

AN:

37992

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25160

East Asian (EAS)

AF:

0.00

AC:

AN:

36616

South Asian (SAS)

AF:

0.00

AC:

AN:

81674

European-Finnish (FIN)

AF:

0.00

AC:

AN:

45042

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5678

European-Non Finnish (NFE)

AF:

0.00000646

AC:

AN:

1084404

Other (OTH)

AF:

0.00

AC:

AN:

58272

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.489

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152224

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74364

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41458

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.500

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

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:

0.0000712

Hom.:

Bravo

AF:

0.0000151

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Progressive sclerosing poliodystrophy

Uncertain:2

Oct 01, 2018

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The NM_002693.2:c.431A>G (NP_002684.1:p.Gln144Arg) [GRCH38: NC_000015.10:g.89333324T>C] variant in POLG gene is interpretated to be a Uncertain Significance based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. BP4:Computational evidence/predictors indicate no impact on the POLG structure, function, or protein-protein interaction. Based on the evidence criteria codes applied, the variant is suggested to be Uncertain Significance. -

Jun 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces glutamine, which is neutral and polar, with arginine, which is basic and polar, at codon 144 of the POLG protein (p.Gln144Arg). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with POLG-related conditions. ClinVar contains an entry for this variant (Variation ID: 587834). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on POLG protein function. 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. -

not specified

Uncertain:1

Apr 16, 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.431A>G (p.Gln144Arg) results in a conservative amino acid change located in the exonuclease domain (IPR041336) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 169380 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.431A>G in individuals affected with POLG-Related Spectrum Disorders and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 587834). Based on the evidence outlined above, the variant was classified as uncertain significance. -

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

Jul 22, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Inborn genetic diseases

Uncertain:1

May 06, 2016

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Q144R variant (also known as c.431A>G), located in coding exon 1 of the POLG gene, results from an A to G substitution at nucleotide position 431. The glutamine at codon 144 is replaced by arginine, an amino acid with highly similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6364 samples (12728 alleles) with coverage at this position. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Feb 15, 2022

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.095

BayesDel_addAF

Uncertain

0.11

BayesDel_noAF

Uncertain

-0.080

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.33

T;T

Eigen

Uncertain

0.46

Eigen_PC

Uncertain

0.49

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.91

.;D

M_CAP

Pathogenic

0.38

MetaRNN

Uncertain

0.60

D;D

MetaSVM

Uncertain

0.56

MutationAssessor

Benign

1.8

L;L

PhyloP100

5.9

PrimateAI

Uncertain

0.70

PROVEAN

Benign

-1.1

N;N

REVEL

Uncertain

0.47

Sift

Benign

0.18

T;T

Sift4G

Benign

0.36

T;T

Polyphen

0.99

D;D

Vest4

0.52

MutPred

0.30

Gain of phosphorylation at S147 (P = 0.0885);Gain of phosphorylation at S147 (P = 0.0885);

MVP

0.93

MPC

0.40

ClinPred

0.60

GERP RS

5.1

PromoterAI

0.24

Neutral

(source)

Varity_R

0.41

gMVP

0.62

Mutation Taster

=69/31

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over