rs141538857

Variant summary

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

The NM_002693.3(POLG):​c.2220C>T​(p.Asn740Asn) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000768 in 1,614,032 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 0.000092 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000075 ( 0 hom. )

Consequence

POLG
NM_002693.3 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:6

Conservation

PhyloP100: -0.998

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=-0.55).
BP6
Variant 15-89323449-G-A is Benign according to our data. Variant chr15-89323449-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 258790.
BP7
Synonymous conserved (PhyloP=-0.998 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POLGNM_002693.3 linkc.2220C>T p.Asn740Asn synonymous_variant Exon 13 of 23 ENST00000268124.11 NP_002684.1
POLGNM_001126131.2 linkc.2220C>T p.Asn740Asn synonymous_variant Exon 13 of 23 NP_001119603.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POLGENST00000268124.11 linkc.2220C>T p.Asn740Asn synonymous_variant Exon 13 of 23 1 NM_002693.3 ENSP00000268124.5

Frequencies

GnomAD3 genomes
AF:
0.0000920
AC:
14
AN:
152206
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.0000942
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000176
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000915
AC:
23
AN:
251376
AF XY:
0.0000810
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000231
Gnomad ASJ exome
AF:
0.0000992
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.0000968
Gnomad OTH exome
AF:
0.000326
GnomAD4 exome
AF:
0.0000753
AC:
110
AN:
1461708
Hom.:
0
Cov.:
31
AF XY:
0.0000811
AC XY:
59
AN XY:
727170
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000179
AC:
8
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.0000765
AC:
2
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86254
European-Finnish (FIN)
AF:
0.0000749
AC:
4
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000827
AC:
92
AN:
1111848
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
Heterozygous variant carriers
0
6
11
17
22
28
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:
0.0000919
AC:
14
AN:
152324
Hom.:
0
Cov.:
33
AF XY:
0.0000806
AC XY:
6
AN XY:
74482
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41568
American (AMR)
AF:
0.0000653
AC:
1
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.0000942
AC:
1
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000176
AC:
12
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.496
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.000159
Hom.:
0
Bravo
AF:
0.0000718
EpiCase
AF:
0.000218
EpiControl
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Mar 06, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

POLG: BP4, BP7 -

not specified Benign:2
-
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 05, 2015
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. -

Progressive sclerosing poliodystrophy Benign:2
Jan 24, 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.2220C>T (NP_002684.1:p.Asn740=) [GRCH38: NC_000015.10:g.89323449G>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. -

Inborn genetic diseases Benign:1
Nov 22, 2016
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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.55
CADD
Benign
0.20
DANN
Benign
0.63
PhyloP100
-1.0

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: rs141538857; hg19: chr15-89866680; API