rs776437525

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_Strong

The NM_002693.3(POLG):c.1001G>A(p.Arg334Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,613,904 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 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. R334R) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 1.05

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 links:

POLGARF (HGNC:):

POLGARF links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.03610155).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
POLG	NM_002693.3 linkuse as main transcript	c.1001G>A	p.Arg334Lys	missense_variant	4/23	ENST00000268124.11
POLGARF	NM_001406557.1 linkuse as main transcript	c.*273G>A		3_prime_UTR_variant	4/23
POLG	NM_001126131.2 linkuse as main transcript	c.1001G>A	p.Arg334Lys	missense_variant	4/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLG	ENST00000268124.11 linkuse as main transcript	c.1001G>A	p.Arg334Lys	missense_variant	4/23	1	NM_002693.3	P1

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152244

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000265

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

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251054

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135706

show subpopulations

Gnomad AFR exome

AF:

0.000308

Gnomad AMR exome

AF:

0.00

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461660

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727114

show subpopulations

Gnomad4 AFR exome

AF:

0.000239

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000723

AC:

AN:

152244

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74370

show subpopulations

Gnomad4 AFR

AF:

0.000265

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:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000642

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Progressive sclerosing poliodystrophy

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Oct 26, 2022	This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 334 of the POLG protein (p.Arg334Lys). This variant is present in population databases (rs776437525, gnomAD 0.03%). 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: 405571). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt POLG protein function. 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine	Oct 01, 2018	The NM_002693.2:c.1001G>A (NP_002684.1:p.Arg334Lys) [GRCH38: NC_000015.10:g.89328965C>T] variant in POLG gene is interpretated to be a Uncertain Significance based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. BP4:Computational evidence/predictors indicate no impact on the POLG structure, function, or protein-protein interaction. PM2:This variant is absent in key population databases. Based on the evidence criteria codes applied, the variant is suggested to be Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.075

BayesDel_addAF

Benign

-0.30

BayesDel_noAF

Benign

-0.36

Cadd

Benign

9.3

Dann

Benign

0.43

DEOGEN2

Benign

0.20

T;T

Eigen

Benign

-0.88

Eigen_PC

Benign

-0.83

FATHMM_MKL

Benign

0.37

M_CAP

Benign

0.051

MetaRNN

Benign

0.036

T;T

MetaSVM

Benign

-0.60

MutationAssessor

Benign

0.23

N;N

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.25

PROVEAN

Benign

-0.15

N;N

REVEL

Benign

0.17

Sift

Benign

0.95

T;T

Sift4G

Benign

0.89

T;T

Polyphen

0.0

B;B

Vest4

0.13

MVP

0.81

MPC

0.15

ClinPred

0.0041

GERP RS

1.8

Varity_R

0.034

gMVP

0.37

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.050

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over