rs781181789

chr15-89328761-C-Gchr15-89328761-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_002693.3(POLG):c.1094G>C(p.Gly365Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,786 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G365E) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: POLG NM_002693.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.73

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]

POLGARF (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.824

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLG	NM_002693.3	c.1094G>C	p.Gly365Ala	missense_variant	5/23	ENST00000268124.11
POLGARF	NM_001406557.1	c.*366G>C		3_prime_UTR_variant	5/23
POLG	NM_001126131.2	c.1094G>C	p.Gly365Ala	missense_variant	5/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLG	ENST00000268124.11	c.1094G>C	p.Gly365Ala	missense_variant	5/23	1	NM_002693.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461786 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727194

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Progressive sclerosing poliodystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 14, 2018

This sequence change replaces glycine with alanine at codon 365 of the POLG protein (p.Gly365Ala). The glycine residue is highly conserved and there is a small physicochemical difference between glycine and alanine. This variant is not present in population databases (ExAC no frequency). This variant has been reported in an individual affected with an adult neurological disease (PMID: 25118206). Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.35
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.80	D;D
Eigen	Pathogenic	0.96
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Uncertain	0.19	D
MetaRNN	Pathogenic	0.82	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.8	M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-2.9	D;D
REVEL	Pathogenic	0.87
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0050	D;D
Polyphen		1.0	D;D
Vest4		0.66
MutPred		0.42		Loss of relative solvent accessibility (P = 0.0414);Loss of relative solvent accessibility (P = 0.0414);
MVP		0.99
MPC		0.68
ClinPred		0.98	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.75
gMVP		0.62

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

Other links and lift over

dbSNP: rs781181789; hg19: chr15-89871992;