17-64477918-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_007215.4(POLG2):c.1363C>A(p.Leu455Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,613,748 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. L455L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

POLG2
NM_007215.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 2.18

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]

POLG2 links:

MILR1 (HGNC:):

MILR1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLG2	NM_007215.4 linkuse as main transcript	c.1363C>A	p.Leu455Met	missense_variant	8/8	ENST00000539111.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLG2	ENST00000539111.7 linkuse as main transcript	c.1363C>A	p.Leu455Met	missense_variant	8/8	1	NM_007215.4	P1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152130

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:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000796

AC:

AN:

251188

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135790

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000192

AC:

AN:

1461618

Hom.:

Cov.:

AF XY:

0.0000179

AC XY:

AN XY:

727100

show subpopulations

Gnomad4 AFR exome

AF:

0.00

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:

0.0000216

Gnomad4 OTH exome

AF:

0.0000663

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152130

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74308

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

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000113

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary spastic paraplegia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

Feb 01, 2019

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 14, 2023

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. 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 disruptive. ClinVar contains an entry for this variant (Variation ID: 1343946). This variant has not been reported in the literature in individuals affected with POLG2-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.002%). This sequence change replaces leucine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 455 of the POLG2 protein (p.Leu455Met). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.17

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

-0.040

Cadd

Benign

Dann

Uncertain

1.0

DEOGEN2

Benign

0.097

Eigen

Uncertain

0.41

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Uncertain

0.87

LIST_S2

Uncertain

0.86

M_CAP

Uncertain

0.19

MetaRNN

Uncertain

0.70

MetaSVM

Uncertain

0.63

MutationAssessor

Pathogenic

3.0

MutationTaster

Benign

0.90

PrimateAI

Uncertain

0.52

PROVEAN

Benign

-0.78

REVEL

Uncertain

0.57

Sift

Uncertain

0.022

Sift4G

Uncertain

0.051

Polyphen

1.0

Vest4

0.47

MutPred

0.64

Gain of disorder (P = 0.0725);

MVP

0.91

MPC

0.59

ClinPred

0.78

GERP RS

2.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.30

gMVP

0.55

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