rs796052887

Variant names:

• chr15-89322748-C-G
• rs796052887
• NM_002693.3:c.2420G>C

Your query was ambiguous. Multiple possible variants found:

• chr15-89322748-C-G
• chr15-89322748-C-T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_002693.3(POLG):​c.2420G>C​(p.Arg807Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,650 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R807C) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: POLG NM_002693.3 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.54
• Publications: 12 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: Pathogenic. The variant received 12 ACMG points.

• PM1: In a helix (size 22) in uniprot entity DPOG1_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) 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 chr15-89322749-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 279982.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 15-89322748-C-G is Pathogenic according to our data. Variant chr15-89322748-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 2736252.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLG	NM_002693.3	c.2420G>C	p.Arg807Pro	missense_variant	Exon 14 of 23	ENST00000268124.11	NP_002684.1
POLG	NM_001126131.2	c.2420G>C	p.Arg807Pro	missense_variant	Exon 14 of 23		NP_001119603.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLG	ENST00000268124.11	c.2420G>C	p.Arg807Pro	missense_variant	Exon 14 of 23	1	NM_002693.3	ENSP00000268124.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461650 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727110

African (AFR) AF: 0.0000299 AC: 1 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53362

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5724

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111924

Other (OTH) AF: 0.00 AC: 0 AN: 60372

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Progressive sclerosing poliodystrophy Pathogenic:1

Mar 03, 2023

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 proline, which is neutral and non-polar, at codon 807 of the POLG protein (p.Arg807Pro). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of autosomal recessive POLG-related disorders (PMID: 14635118). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt POLG protein function. This variant disrupts the p.Arg807 amino acid residue in POLG. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 16919951, 21357833, 28471437). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.98	D;D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.95	.;D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.5	H;H
PhyloP100		7.5
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-6.9	D;D
REVEL	Pathogenic	0.99
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.86
MutPred		0.96		Loss of MoRF binding (P = 0.0783);Loss of MoRF binding (P = 0.0783);
MVP		0.99
MPC		0.80
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.98
gMVP		0.97
Mutation Taster		=1/99	disease causing

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: rs796052887; hg19: chr15-89865979;