rs183811122

chr15-89321826-G-Achr15-89321826-G-C

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_Strong BP6_Very_Strong BP7

The NM_002693.3(POLG):c.2508C>T(p.Leu836=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,614,080 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. L836L) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: POLG NM_002693.3 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:4
• Conservation: PhyloP100: 1.48

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 Benign. Variant got -13 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.48).
• BP6: Variant 15-89321826-G-A is Benign according to our data. Variant chr15-89321826-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 458706.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=1.48 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLG	NM_002693.3	c.2508C>T	p.Leu836=	synonymous_variant	16/23	ENST00000268124.11
POLGARF	NM_001406557.1	c.*1780C>T		3_prime_UTR_variant	16/23
POLG	NM_001126131.2	c.2508C>T	p.Leu836=	synonymous_variant	16/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLG	ENST00000268124.11	c.2508C>T	p.Leu836=	synonymous_variant	16/23	1	NM_002693.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152200 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000193

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251434 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135904

Gnomad AFR exome AF: 0.000185

Gnomad AMR exome AF: 0.00

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: 0.00000753 AC: 11 AN: 1461762 Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5 AN XY: 727188

Gnomad4 AFR exome AF: 0.000269

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000525 AC: 8 AN: 152318 Hom.: 0 Cov.: 33 AF XY: 0.0000537 AC XY: 4 AN XY: 74480

Gnomad4 AFR AF: 0.000192

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000642

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Likely benign

Submissions summary: Benign:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Benign:2

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Sep 11, 2018	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Aug 01, 2021	- -

Progressive sclerosing poliodystrophy Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Wong Mito Lab, Molecular and Human Genetics, Baylor College of Medicine	Oct 01, 2018	The NM_002693.2:c.2508C>T (NP_002684.1:p.Leu836=) [GRCH38: NC_000015.10:g.89321826G>A] variant in POLG gene is interpretated to be a Likely Benign based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. BP4:Computational evidence/predictors indicate no impact on the POLG structure, function, or protein-protein interaction. BP7:The variant is silent with non predicted splice impact. Based on the evidence criteria codes applied, the variant is suggested to be Likely Benign. -
Likely benign, criteria provided, single submitter	clinical testing	Invitae	Oct 03, 2023	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.48
Cadd	Benign	4.5
Dann	Benign	0.86

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: rs183811122; hg19: chr15-89865057;