rs767138032

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PP3_StrongPP5

The NM_002693.3(POLG):c.3412C>T(p.Arg1138Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,862 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 9.37

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.985

PP5

Variant 15-89318611-G-A is Pathogenic according to our data. Variant chr15-89318611-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 559173.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=2, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3 link	c.3412C>T	p.Arg1138Cys	missense_variant	Exon 21 of 23	ENST00000268124.11	NP_002684.1	P54098E5KNU5
POLG	NM_001126131.2 link	c.3412C>T	p.Arg1138Cys	missense_variant	Exon 21 of 23		NP_001119603.1	P54098E5KNU5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11 link	c.3412C>T	p.Arg1138Cys	missense_variant	Exon 21 of 23	1	NM_002693.3	ENSP00000268124.5		P54098

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251432

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135886

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461862

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727232

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:

0.00000360

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Progressive sclerosing poliodystrophy

Pathogenic:2

Nov 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 1138 of the POLG protein (p.Arg1138Cys). This variant is present in population databases (rs767138032, gnomAD 0.003%). This missense change has been observed in individual(s) with autosomal recessive SANDO syndrome (PMID: 18585914, 27538604). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 559173). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt POLG protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Oct 01, 2018

Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NM_002693.2:c.3412C>T (NP_002684.1:p.Arg1138Cys) [GRCH38: NC_000015.10:g.89318611G>A] variant in POLG gene is interpretated to be a Likely Pathogenic based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. PM2:This variant is absent in key population databases. PM3:Detected in trans with a pathogenic variant for Mitochondrial DNA depletion syndrome 4A (Alpers type) which is a recessive disorder. PP2:This is a missense variant in POLG with a low rate of benign and high rate of pathogenic missense variations. PP4:Patient's phenotype or family history is highly specific for POLG. Based on the evidence criteria codes applied, the variant is suggested to be Likely Pathogenic. -

not provided

Uncertain:2

Mar 15, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 33791913, 18546365, 30936349, 30451971, 20513108, 27538604, 32347949, 24508722, 20220442, 18585914) -

Feb 29, 2016

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not specified

Uncertain:1

Aug 05, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: POLG c.3412C>T (p.Arg1138Cys) results in a non-conservative amino acid change located in the DNA-directed DNA polymerase, family A, palm domain (IPR001098), cluster 1 of the encoded protein sequence. Cluster 1 mutations are predicted to cause a primary defect in pol activity and affect residues involved directly in catalysis or indirectly by affecting architectural residues that may disrupt the position of catalytic residues (Farnum_2014). Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251432 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.3412C>T has been reported in the literature as a compound heterozygous genotype in at-least one individual affected with POLG-Related Spectrum Disorder, diagnosed as autosomal recessive progressive external opthalmoplegia (PEO) who has been widely cited by others (example, Wong_2008, Milone_2008 cited by others example, Li_2021). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (VUS, n=2, Likely pathogenic, n=1). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.87

BayesDel_addAF

Pathogenic

0.53

BayesDel_noAF

Pathogenic

0.60

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.97

D;D

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.93

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

1.0

.;D

M_CAP

Pathogenic

0.38

MetaRNN

Pathogenic

0.99

D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.5

H;H

PrimateAI

Pathogenic

0.81

PROVEAN

Pathogenic

-7.5

D;D

REVEL

Pathogenic

0.97

Sift

Pathogenic

0.0

D;D

Sift4G

Pathogenic

0.0

D;D

Polyphen

1.0

D;D

Vest4

0.89

MutPred

0.90

Loss of disorder (P = 0.0267);Loss of disorder (P = 0.0267);

MVP

0.99

MPC

0.77

ClinPred

1.0

GERP RS

5.3

Varity_R

0.91

gMVP

0.89

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