rs1064794214

Variant names:

• chr15-89325525-G-A
• rs1064794214
• NM_002693.3:c.1874C>T

Your query was ambiguous. Multiple possible variants found:

• chr15-89325525-G-A
• chr15-89325525-G-C

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP3_Moderate PP5

The NM_002693.3(POLG):​c.1874C>T​(p.Pro625Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P625R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: POLG NM_002693.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 10.0
• Publications: 1 publications found

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 Gene-Disease associations (from GenCC):

• progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• mitochondrial DNA depletion syndrome 4a

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Orphanet, G2P
• sensory ataxic neuropathy, dysarthria, and ophthalmoparesis

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, G2P
• autosomal dominant progressive external ophthalmoplegia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive progressive external ophthalmoplegia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• mitochondrial neurogastrointestinal encephalomyopathy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• recessive mitochondrial ataxia syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• spinocerebellar ataxia with epilepsy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Leigh syndrome

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 14 uncertain in NM_002693.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr15-89325525-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2736255.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.909
• PP5: Variant 15-89325525-G-A is Pathogenic according to our data. Variant chr15-89325525-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 419975.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3	c.1874C>T	p.Pro625Leu	missense_variant	Exon 10 of 23	ENST00000268124.11	NP_002684.1
POLG	NM_001126131.2	c.1874C>T	p.Pro625Leu	missense_variant	Exon 10 of 23		NP_001119603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11	c.1874C>T	p.Pro625Leu	missense_variant	Exon 10 of 23	1	NM_002693.3	ENSP00000268124.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Progressive sclerosing poliodystrophy Pathogenic:1 Uncertain:1

Oct 01, 2018

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NM_002693.2:c.1874C>T (NP_002684.1:p.Pro625Leu) [GRCH38: NC_000015.10:g.89325525G>A] variant in POLG gene is interpretated to be a Pathogenic based on ACMG guidelines (PMID: 25741868). This variant has been reported in PMID:21880868 . This variant meets the following evidence codes reported in the ACMG-guideline. PS1:This variation causes same amino-acid change as an established pathogenic variant. 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. PP1:This variant is co-segregated with Mitochondrial DNA depletion syndrome 4A (Alpers type) in multiple affected family members. 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 Pathogenic. -

Dec 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 625 of the POLG protein (p.Pro625Leu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of POLG-related conditions (PMID: 21880868). ClinVar contains an entry for this variant (Variation ID: 419975). 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%. 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. -

not provided Pathogenic:1

Jul 10, 2025

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in an individual with seizures, developmental delay, hypotonia, ataxia, spasticity, muscle weakness, and an abnormal muscle biopsy; however, a second POLG variant was not described in the individual (PMID: 21880868); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 21880868, Betler2024[Review], 39091670) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.68
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;D
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	.;D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.91	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.9	M;M
PhyloP100		10
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-8.1	D;D
REVEL	Pathogenic	0.93
Sift	Benign	0.051	T;T
Sift4G	Benign	0.065	T;T
Polyphen		1.0	D;D
Vest4		0.70
MutPred		0.69		Loss of disorder (P = 0.1);Loss of disorder (P = 0.1);
MVP		0.98
MPC		0.66
ClinPred		1.0	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.61
gMVP		0.91
Mutation Taster		=24/76	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1064794214; hg19: chr15-89868756;