15-89323820-C-A

Position:

chr15-89323820-C-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_002693.3(POLG):c.2152G>T(p.Ala718Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,426 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A718V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: -0.0990

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 -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.09211466).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
POLG	NM_002693.3 linkuse as main transcript	c.2152G>T	p.Ala718Ser	missense_variant	12/23	ENST00000268124.11
POLGARF	NM_001406557.1 linkuse as main transcript	c.*1424G>T		3_prime_UTR_variant	12/23
POLG	NM_001126131.2 linkuse as main transcript	c.2152G>T	p.Ala718Ser	missense_variant	12/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLG	ENST00000268124.11 linkuse as main transcript	c.2152G>T	p.Ala718Ser	missense_variant	12/23	1	NM_002693.3	P1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152192

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

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:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000795

AC:

AN:

251434

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135900

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

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:

0.00000137

AC:

AN:

1461234

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726978

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152192

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74350

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.0000654

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:

0.0000340

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 18, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Mar 17, 2021	Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Progressive sclerosing poliodystrophy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 27, 2022

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 718 of the POLG protein (p.Ala718Ser). This variant is present in population databases (rs755783536, gnomAD 0.004%). 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: 432235). 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. 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

0.076

BayesDel_addAF

Benign

-0.069

BayesDel_noAF

Benign

-0.25

CADD

Benign

5.3

DANN

Benign

0.40

DEOGEN2

Benign

0.19

T;T

Eigen

Benign

-1.0

Eigen_PC

Benign

-0.97

FATHMM_MKL

Benign

0.33

LIST_S2

Benign

0.71

.;T

M_CAP

Benign

0.051

MetaRNN

Benign

0.092

T;T

MetaSVM

Uncertain

0.14

MutationAssessor

Benign

0.0

N;N

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.32

PROVEAN

Benign

0.080

N;N

REVEL

Benign

0.22

Sift

Benign

0.42

T;T

Sift4G

Benign

0.62

T;T

Polyphen

0.0030

B;B

Vest4

0.22

MVP

0.77

MPC

0.14

ClinPred

0.025

GERP RS

2.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.052

gMVP

0.27

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.060

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