NM_002693.3:c.3076C>T

Variant names:

• chr15-89319256-G-A
• rs760043525
• NM_002693.3:c.3076C>T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_002693.3(POLG):​c.3076C>T​(p.Arg1026Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000212 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000021 (0 hom.)
• Consequence: POLG NM_002693.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 4.29

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.877

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3	c.3076C>T	p.Arg1026Cys	missense_variant	Exon 19 of 23	ENST00000268124.11	NP_002684.1
POLG	NM_001126131.2	c.3076C>T	p.Arg1026Cys	missense_variant	Exon 19 of 23		NP_001119603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11	c.3076C>T	p.Arg1026Cys	missense_variant	Exon 19 of 23	1	NM_002693.3	ENSP00000268124.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000159 AC: 4 AN: 251418 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135880

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000212 AC: 31 AN: 1461876 Hom.: 0 Cov.: 34 AF XY: 0.0000234 AC XY: 17 AN XY: 727242

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000151

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000144

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Progressive sclerosing poliodystrophy;C1834846:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1;C1843851:Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis;C3150914:Mitochondrial DNA depletion syndrome 4b;C4225153:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 1;C4551995:Mitochondrial DNA depletion syndrome 1 Uncertain:1

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

POLG-Related Spectrum Disorders Uncertain:1

Apr 10, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

POLG-related disorder Uncertain:1

Apr 27, 2019

Genomic Research Center, Shahid Beheshti University of Medical Sciences

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Uncertain:1

Apr 02, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Has not been previously published as pathogenic or benign to our knowledge; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Pathogenic	0.18
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.81	D;D
Eigen	Uncertain	0.54
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.89	.;D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.88	D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Uncertain	2.3	M;M
PrimateAI	Benign	0.35	T
PROVEAN	Uncertain	-2.7	D;D
REVEL	Pathogenic	0.83
Sift	Uncertain	0.029	D;D
Sift4G	Uncertain	0.0090	D;D
Polyphen		1.0	D;D
Vest4		0.77
MutPred		0.56		Loss of MoRF binding (P = 0.0074);Loss of MoRF binding (P = 0.0074);
MVP		0.97
MPC		0.76
ClinPred		0.95	D
GERP RS		3.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Varity_R		0.34
gMVP		0.74

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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

Other links and lift over

dbSNP: rs760043525; hg19: chr15-89862487;