NM_002693.3:c.2149C>T

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_StrongBP6BP7

The NM_002693.3(POLG):​c.2149C>T​(p.Leu717Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000403 in 1,613,496 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00022 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

POLG
NM_002693.3 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:5

Conservation

PhyloP100: 0.520

Publications

0 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.84).
BP6
Variant 15-89323823-G-A is Benign according to our data. Variant chr15-89323823-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 378413.
BP7
Synonymous conserved (PhyloP=0.52 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002693.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
POLG
NM_002693.3
MANE Select
c.2149C>Tp.Leu717Leu
synonymous
Exon 12 of 23NP_002684.1
POLG
NM_001126131.2
c.2149C>Tp.Leu717Leu
synonymous
Exon 12 of 23NP_001119603.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
POLG
ENST00000268124.11
TSL:1 MANE Select
c.2149C>Tp.Leu717Leu
synonymous
Exon 12 of 23ENSP00000268124.5
POLG
ENST00000442287.6
TSL:1
c.2149C>Tp.Leu717Leu
synonymous
Exon 12 of 23ENSP00000399851.2
POLG
ENST00000636937.2
TSL:5
c.2149C>Tp.Leu717Leu
synonymous
Exon 12 of 23ENSP00000516154.1

Frequencies

GnomAD3 genomes
AF:
0.000217
AC:
33
AN:
152172
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000748
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.00
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251436
AF XY:
0.0000221
show subpopulations
Gnomad AFR exome
AF:
0.000308
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000219
AC:
32
AN:
1461324
Hom.:
0
Cov.:
32
AF XY:
0.0000138
AC XY:
10
AN XY:
727008
show subpopulations
African (AFR)
AF:
0.000867
AC:
29
AN:
33466
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5750
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111510
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000217
AC:
33
AN:
152172
Hom.:
0
Cov.:
33
AF XY:
0.000229
AC XY:
17
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.000748
AC:
31
AN:
41440
American (AMR)
AF:
0.0000655
AC:
1
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68020
Other (OTH)
AF:
0.000478
AC:
1
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.490
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000131
Hom.:
0
Bravo
AF:
0.000212

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Dec 26, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Aug 28, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Progressive sclerosing poliodystrophy Benign:2
Oct 01, 2018
Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The NM_002693.2:c.2149C>T (NP_002684.1:p.Leu717=) [GRCH38: NC_000015.10:g.89323823G>A] variant in POLG gene is interpretated to be a Likely Benign 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. BP7:The variant is silent with non predicted splice impact. Based on the evidence criteria codes applied, the variant is suggested to be Likely Benign.

Jan 30, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Inborn genetic diseases Benign:1
May 23, 2018
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely 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.

POLG-related disorder Benign:1
Jun 02, 2021
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.84
CADD
Benign
0.96
DANN
Benign
0.39
PhyloP100
0.52
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs779515404; hg19: chr15-89867054; COSMIC: COSV99175079; COSMIC: COSV99175079; API