rs147404477

Variant summary

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

The NM_002693.3(POLG):​c.1275C>T​(p.Ala425Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00067 in 1,613,794 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). Synonymous variant affecting the same amino acid position (i.e. A425A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00056 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00068 ( 0 hom. )

Consequence

POLG
NM_002693.3 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:9

Conservation

PhyloP100: -1.61

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=-0.71).
BP6
Variant 15-89327325-G-A is Benign according to our data. Variant chr15-89327325-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 138774.
BP7
Synonymous conserved (PhyloP=-1.61 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POLGNM_002693.3 linkc.1275C>T p.Ala425Ala synonymous_variant Exon 7 of 23 ENST00000268124.11 NP_002684.1
POLGNM_001126131.2 linkc.1275C>T p.Ala425Ala synonymous_variant Exon 7 of 23 NP_001119603.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POLGENST00000268124.11 linkc.1275C>T p.Ala425Ala synonymous_variant Exon 7 of 23 1 NM_002693.3 ENSP00000268124.5

Frequencies

GnomAD3 genomes
AF:
0.000565
AC:
86
AN:
152154
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000193
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000720
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.000565
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000823
Gnomad OTH
AF:
0.00143
GnomAD2 exomes
AF:
0.000347
AC:
87
AN:
250788
AF XY:
0.000287
show subpopulations
Gnomad AFR exome
AF:
0.000124
Gnomad AMR exome
AF:
0.000347
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000279
Gnomad NFE exome
AF:
0.000547
Gnomad OTH exome
AF:
0.000653
GnomAD4 exome
AF:
0.000681
AC:
995
AN:
1461522
Hom.:
0
Cov.:
34
AF XY:
0.000696
AC XY:
506
AN XY:
727070
show subpopulations
African (AFR)
AF:
0.000179
AC:
6
AN:
33480
American (AMR)
AF:
0.000492
AC:
22
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000696
AC:
6
AN:
86250
European-Finnish (FIN)
AF:
0.000264
AC:
14
AN:
53122
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5724
European-Non Finnish (NFE)
AF:
0.000815
AC:
906
AN:
1111996
Other (OTH)
AF:
0.000679
AC:
41
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.460
Heterozygous variant carriers
0
56
111
167
222
278
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
34
68
102
136
170
<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:
0.000565
AC:
86
AN:
152272
Hom.:
0
Cov.:
33
AF XY:
0.000470
AC XY:
35
AN XY:
74454
show subpopulations
African (AFR)
AF:
0.000193
AC:
8
AN:
41554
American (AMR)
AF:
0.000719
AC:
11
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5182
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4824
European-Finnish (FIN)
AF:
0.000565
AC:
6
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000823
AC:
56
AN:
68008
Other (OTH)
AF:
0.00142
AC:
3
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.503
Heterozygous variant carriers
0
4
8
13
17
21
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:
0.000498
Hom.:
0
Bravo
AF:
0.000604
EpiCase
AF:
0.000545
EpiControl
AF:
0.000652

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:9
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:3
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

Aug 23, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Aug 01, 2025
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

POLG: BP4, BP7

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

not specified Benign:2
Aug 07, 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.

Dec 01, 2020
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Progressive sclerosing poliodystrophy Benign:2
Feb 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
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:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The NM_002693.2:c.1275C>T (NP_002684.1:p.Ala425=) [GRCH38: NC_000015.10:g.89327325G>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. BS1:The minor allele frequency of this allele is high for 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 Likely Benign.

Hereditary spastic paraplegia Uncertain:1
Aug 16, 2021
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Inborn genetic diseases Benign:1
Dec 20, 2017
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
Nov 21, 2019
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 v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.71
CADD
Benign
7.0
DANN
Benign
0.63
PhyloP100
-1.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=99/1
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs147404477; hg19: chr15-89870556; COSMIC: COSV51519337; COSMIC: COSV51519337; API