rs115109291

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM1BP4_StrongBP6

The NM_002693.3(POLG):​c.408C>G​(p.Asp136Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000149 in 1,568,212 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D136Y) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00076 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000083 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

3
16

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:4

Conservation

PhyloP100: 1.66

Publications

3 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]
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]

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_002693.3
BP4
Computational evidence support a benign effect (MetaRNN=0.009656161).
BP6
Variant 15-89333347-G-C is Benign according to our data. Variant chr15-89333347-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 206576.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POLGNM_002693.3 linkc.408C>G p.Asp136Glu missense_variant Exon 2 of 23 ENST00000268124.11 NP_002684.1 P54098E5KNU5
POLGNM_001126131.2 linkc.408C>G p.Asp136Glu missense_variant Exon 2 of 23 NP_001119603.1 P54098E5KNU5
POLGARFNM_001430120.1 linkc.463C>G p.Pro155Ala missense_variant Exon 1 of 2 NP_001417049.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POLGENST00000268124.11 linkc.408C>G p.Asp136Glu missense_variant Exon 2 of 23 1 NM_002693.3 ENSP00000268124.5 P54098
POLGARFENST00000706918.1 linkc.463C>G p.Pro155Ala missense_variant Exon 1 of 2 ENSP00000516626.1 A0A3B3IS91

Frequencies

GnomAD3 genomes
AF:
0.000755
AC:
115
AN:
152252
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.00277
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000227
AC:
40
AN:
176174
AF XY:
0.000104
show subpopulations
Gnomad AFR exome
AF:
0.00361
Gnomad AMR exome
AF:
0.0000721
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:
0.000209
GnomAD4 exome
AF:
0.0000833
AC:
118
AN:
1415842
Hom.:
0
Cov.:
32
AF XY:
0.0000699
AC XY:
49
AN XY:
701130
show subpopulations
African (AFR)
AF:
0.00316
AC:
102
AN:
32316
American (AMR)
AF:
0.000129
AC:
5
AN:
38830
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25302
East Asian (EAS)
AF:
0.00
AC:
0
AN:
37096
South Asian (SAS)
AF:
0.00
AC:
0
AN:
82110
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
44950
Middle Eastern (MID)
AF:
0.000352
AC:
2
AN:
5674
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1090924
Other (OTH)
AF:
0.000153
AC:
9
AN:
58640
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
8
16
23
31
39
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.000761
AC:
116
AN:
152370
Hom.:
0
Cov.:
34
AF XY:
0.000751
AC XY:
56
AN XY:
74520
show subpopulations
African (AFR)
AF:
0.00279
AC:
116
AN:
41592
American (AMR)
AF:
0.00
AC:
0
AN:
15312
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10632
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.499
Heterozygous variant carriers
0
7
13
20
26
33
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:
0.00
Hom.:
0
Bravo
AF:
0.000869
ESP6500AA
AF:
0.00116
AC:
5
ESP6500EA
AF:
0.000118
AC:
1
ExAC
AF:
0.000176
AC:
21

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:4Benign:1
Jan 05, 2024
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

See Variant Classification Assertion Criteria. -

Apr 17, 2017
Center for Pediatric Genomic Medicine, Children's Mercy Hospital and Clinics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 13, 2021
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Aug 29, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Apr 27, 2023
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

BP4 -

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.408C>G (NP_002684.1:p.Asp136Glu) [GRCH38: NC_000015.10:g.89333347G>C] 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. Based on the evidence criteria codes applied, the variant is suggested to be Likely Benign. -

Jan 19, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Dec 03, 2018
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.D136E variant (also known as c.408C>G), located in coding exon 1 of the POLG gene, results from a C to G substitution at nucleotide position 408. The aspartic acid at codon 136 is replaced by glutamic acid, an amino acid with highly similar properties. This alteration was detected in two brothers with epilepsy who had p.Q45R on the other chromosome; the variant was not found in 100 control individuals (Blok MJ et al. J. Med. Genet., 2009 Nov;46:776-85). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

POLG-related disorder Benign:1
Jun 27, 2022
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
AlphaMissense
Benign
0.30
BayesDel_addAF
Benign
-0.34
T
BayesDel_noAF
Benign
-0.26
CADD
Benign
23
DANN
Benign
0.78
DEOGEN2
Benign
0.25
T;T
Eigen
Benign
-0.29
Eigen_PC
Benign
-0.15
FATHMM_MKL
Uncertain
0.88
D
LIST_S2
Benign
0.61
.;T
M_CAP
Uncertain
0.14
D
MetaRNN
Benign
0.0097
T;T
MetaSVM
Benign
-0.41
T
MutationAssessor
Benign
1.3
L;L
PhyloP100
1.7
PrimateAI
Uncertain
0.62
T
PROVEAN
Benign
0.080
N;N
REVEL
Benign
0.22
Sift
Benign
1.0
T;T
Sift4G
Benign
1.0
T;T
Polyphen
0.43
B;B
Vest4
0.35
MutPred
0.42
Gain of disorder (P = 0.2129);Gain of disorder (P = 0.2129);
MVP
0.88
MPC
0.16
ClinPred
0.014
T
GERP RS
3.1
PromoterAI
0.020
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.20
gMVP
0.51
Mutation Taster
=82/18
polymorphism

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

Other links and lift over

dbSNP: rs115109291; hg19: chr15-89876578; API