rs762878459

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM1

The NM_002693.3(POLG):c.1385C>T(p.Ser462Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000867 in 1,614,070 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. S462S) has been classified as Likely benign.

Frequency

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

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 9.50

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 Uncertain_significance. Variant got 2 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_002693.3

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
POLG	NM_002693.3 linkuse as main transcript	c.1385C>T	p.Ser462Leu	missense_variant	7/23	ENST00000268124.11
POLGARF	NM_001406557.1 linkuse as main transcript	c.*657C>T		3_prime_UTR_variant	7/23
POLG	NM_001126131.2 linkuse as main transcript	c.1385C>T	p.Ser462Leu	missense_variant	7/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLG	ENST00000268124.11 linkuse as main transcript	c.1385C>T	p.Ser462Leu	missense_variant	7/23	1	NM_002693.3	P1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

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:

0.000207

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:

251472

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135916

show subpopulations

Gnomad AFR exome

AF:

0.00

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:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000889

AC:

AN:

1461862

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727238

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000894

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:

0.00000629

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74356

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:

0.000207

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Dec 05, 2016

A variant of uncertain significance has been identified in the POLG gene. The S462L variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The S462L variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The S462L variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved in mammals. Missense variants in nearby residues (M464T, A467T) have been reported in the Human Gene Mutation Database in association with POLG-related disorders (Stenson et al., 2014). In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 23, 2023

This variant has not been reported in the literature in individuals affected with POLG-related conditions. This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 462 of the POLG protein (p.Ser462Leu). This variant is present in population databases (rs762878459, gnomAD 0.01%). ClinVar contains an entry for this variant (Variation ID: 206595). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Uncertain

0.049

BayesDel_noAF

Uncertain

0.060

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Benign

0.36

T;T

Eigen

Uncertain

0.46

Eigen_PC

Uncertain

0.53

FATHMM_MKL

Pathogenic

0.98

M_CAP

Uncertain

0.14

MetaRNN

Uncertain

0.59

D;D

MetaSVM

Uncertain

0.18

MutationAssessor

Benign

1.7

L;L

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.63

PROVEAN

Benign

-0.75

N;N

REVEL

Uncertain

0.62

Sift

Benign

0.84

T;T

Sift4G

Benign

0.59

T;T

Polyphen

0.99

D;D

Vest4

0.74

MutPred

0.39

Loss of disorder (P = 0.0176);Loss of disorder (P = 0.0176);

MVP

0.96

MPC

0.56

ClinPred

0.66

GERP RS

5.0

Varity_R

0.24

gMVP

0.61

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

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