rs757804090

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_002693.3(POLG):​c.1349G>T​(p.Gly450Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,614,088 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. G450G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 0.122
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM1
In a helix (size 33) in uniprot entity DPOG1_HUMAN there are 8 pathogenic changes around while only 0 benign (100%) in NM_002693.3
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.121611625).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
POLGNM_002693.3 linkc.1349G>T p.Gly450Val missense_variant Exon 7 of 23 ENST00000268124.11 NP_002684.1 P54098E5KNU5
POLGNM_001126131.2 linkc.1349G>T p.Gly450Val missense_variant Exon 7 of 23 NP_001119603.1 P54098E5KNU5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
POLGENST00000268124.11 linkc.1349G>T p.Gly450Val missense_variant Exon 7 of 23 1 NM_002693.3 ENSP00000268124.5 P54098

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152234
Hom.:
0
Cov.:
33
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251454
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135916
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 SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461854
Hom.:
0
Cov.:
33
AF XY:
0.00000138
AC XY:
1
AN XY:
727230
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152234
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74378
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1
Sep 22, 2017
GeneDx
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The G450V variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge.This variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). The G450V variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties. This substitution occurs at a position that is not conserved. In silico analysis is inconsistent in its predictions as to whether or not the variant isdamaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. -

Progressive sclerosing poliodystrophy Uncertain:1
Jul 05, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 450 of the POLG protein (p.Gly450Val). This variant is present in population databases (rs757804090, gnomAD 0.003%). 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: 452164). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.10
T
BayesDel_noAF
Benign
-0.29
CADD
Benign
16
DANN
Benign
0.73
DEOGEN2
Benign
0.30
T;T
Eigen
Benign
-0.70
Eigen_PC
Benign
-0.61
FATHMM_MKL
Uncertain
0.81
D
LIST_S2
Benign
0.77
.;T
M_CAP
Benign
0.051
D
MetaRNN
Benign
0.12
T;T
MetaSVM
Benign
-0.57
T
MutationAssessor
Benign
1.1
L;L
PrimateAI
Benign
0.27
T
PROVEAN
Benign
-0.36
N;N
REVEL
Benign
0.18
Sift
Benign
0.30
T;T
Sift4G
Benign
0.30
T;T
Polyphen
0.049
B;B
Vest4
0.29
MutPred
0.33
Loss of disorder (P = 0.0381);Loss of disorder (P = 0.0381);
MVP
0.83
MPC
0.22
ClinPred
0.035
T
GERP RS
-0.55
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.038
gMVP
0.20

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs757804090; hg19: chr15-89870482; API