rs148101254

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_StrongBP6

The NM_007215.4(POLG2):​c.674G>A​(p.Arg225Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000706 in 1,614,048 control chromosomes in the GnomAD database, including 1 homozygotes. 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 Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R225R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00016 ( 1 hom., cov: 32)
Exomes 𝑓: 0.000061 ( 0 hom. )

Consequence

POLG2
NM_007215.4 missense

Scores

19

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 0.0500
Variant links:
Genes affected
POLG2 (HGNC:9180): (DNA polymerase gamma 2, accessory subunit) This gene encodes the processivity subunit of the mitochondrial DNA polymerase gamma. The encoded protein forms a heterotrimer containing one catalytic subunit and two processivity subunits. This protein enhances DNA binding and promotes processive DNA synthesis. Mutations in this gene result in autosomal dominant progressive external ophthalmoplegia with mitochondrial DNA deletions.[provided by RefSeq, Sep 2009]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.017912477).
BP6
Variant 17-64492910-C-T is Benign according to our data. Variant chr17-64492910-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 324559.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=3, Likely_benign=2}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
POLG2NM_007215.4 linkuse as main transcriptc.674G>A p.Arg225Gln missense_variant 2/8 ENST00000539111.7

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
POLG2ENST00000539111.7 linkuse as main transcriptc.674G>A p.Arg225Gln missense_variant 2/81 NM_007215.4 P1

Frequencies

GnomAD3 genomes
AF:
0.000164
AC:
25
AN:
152144
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000507
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000795
AC:
20
AN:
251450
Hom.:
0
AF XY:
0.0000368
AC XY:
5
AN XY:
135910
show subpopulations
Gnomad AFR exome
AF:
0.000677
Gnomad AMR exome
AF:
0.000116
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000440
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000609
AC:
89
AN:
1461786
Hom.:
0
Cov.:
31
AF XY:
0.0000591
AC XY:
43
AN XY:
727200
show subpopulations
Gnomad4 AFR exome
AF:
0.000478
Gnomad4 AMR exome
AF:
0.0000894
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000504
Gnomad4 SAS exome
AF:
0.0000232
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000477
Gnomad4 OTH exome
AF:
0.000199
GnomAD4 genome
AF:
0.000164
AC:
25
AN:
152262
Hom.:
1
Cov.:
32
AF XY:
0.000161
AC XY:
12
AN XY:
74434
show subpopulations
Gnomad4 AFR
AF:
0.000505
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000208
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000441
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000839
Hom.:
0
Bravo
AF:
0.000234
ESP6500AA
AF:
0.000908
AC:
4
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000824
AC:
10
EpiCase
AF:
0.00
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingCenter for Pediatric Genomic Medicine, Children's Mercy Hospital and ClinicsNov 22, 2016- -
Uncertain significance, criteria provided, single submitterclinical testingInvitaeNov 13, 2023This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 225 of the POLG2 protein (p.Arg225Gln). This variant is present in population databases (rs148101254, gnomAD 0.06%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with POLG2-related conditions. ClinVar contains an entry for this variant (Variation ID: 324559). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -
Hereditary spastic paraplegia Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingGenome Diagnostics Laboratory, The Hospital for Sick ChildrenDec 12, 2016- -
not specified Benign:1
Likely benign, criteria provided, single submitterclinical testingGeneDxDec 27, 2016This 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 external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 4 Benign:1
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaApr 27, 2017This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.066
BayesDel_addAF
Benign
-0.49
T
BayesDel_noAF
Benign
-0.57
CADD
Benign
12
DANN
Benign
0.81
DEOGEN2
Benign
0.094
T
Eigen
Benign
-1.3
Eigen_PC
Benign
-1.3
FATHMM_MKL
Benign
0.11
N
LIST_S2
Benign
0.64
T
M_CAP
Benign
0.049
D
MetaRNN
Benign
0.018
T
MetaSVM
Benign
-0.87
T
MutationAssessor
Benign
0.0
N
MutationTaster
Benign
1.0
N
PrimateAI
Benign
0.28
T
PROVEAN
Benign
-0.98
N
REVEL
Benign
0.15
Sift
Benign
0.60
T
Sift4G
Benign
0.61
T
Polyphen
0.0010
B
Vest4
0.23
MVP
0.74
MPC
0.15
ClinPred
0.0052
T
GERP RS
1.1
Varity_R
0.045
gMVP
0.12

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: rs148101254; hg19: chr17-62489027; COSMIC: COSV73347032; COSMIC: COSV73347032; API