rs3087379

Positions:

• chr15-89333085-C-A

Variant summary

Our verdict is Benign. Variant got -16 ACMG points: 0P and 16B. BP4_Strong BP6_Very_Strong BS2

The NM_002693.3(POLG):​c.659+11G>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000219 in 1,510,744 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00012 (0 hom., cov: 34)
  • Exomes 𝑓: 0.00023 (4 hom.)
• Consequence: POLG NM_002693.3 intron
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: -0.175

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:56246): (POLG alternative reading frame) This gene uses the same transcript as the POLG gene but has a CUG start codon and an alternate reading frame that makes a 260 aa protein. This protein is distinct from POLG isoforms and may interact with P32 (also known as C1QBP), a mitochondrial matrix protein thought to be involved in the expression of mitochondrial genome-encoded proteins. POLGARF protein may bind P32 and sequester it in the nucleolus. Interestingly, some disease-causing mutations thought to be in POLG may instead be associated with POLGARF. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Benign. Variant got -16 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.64).
• BP6: Variant 15-89333085-C-A is Benign according to our data. Variant chr15-89333085-C-A is described in ClinVar as [Benign]. Clinvar id is 206494.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-89333085-C-A is described in Lovd as [Benign].
• BS2: High Homozygotes in GnomAdExome4 at 4 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLG	NM_002693.3	c.659+11G>T		intron_variant		ENST00000268124.11
POLGARF	NM_001406557.1	c.714+11G>T		intron_variant
POLG	NM_001126131.2	c.659+11G>T		intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLG	ENST00000268124.11	c.659+11G>T		intron_variant		1	NM_002693.3	P1
POLGARF	ENST00000706918.1	c.714+11G>T		intron_variant				P1

Frequencies

GnomAD3 genomes AF: 0.000118 AC: 18 AN: 152222 Hom.: 0 Cov.: 34

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00372

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000352 AC: 59 AN: 167486 Hom.: 0 AF XY: 0.000346 AC XY: 31 AN XY: 89610

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00391

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000381

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000230 AC: 312 AN: 1358404 Hom.: 4 Cov.: 31 AF XY: 0.000292 AC XY: 194 AN XY: 663940

Gnomad4 AFR exome AF: 0.0000333

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000260

Gnomad4 SAS exome AF: 0.00397

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000160

Gnomad4 OTH exome AF: 0.000251

GnomAD4 genome AF: 0.000125 AC: 19 AN: 152340 Hom.: 0 Cov.: 34 AF XY: 0.000188 AC XY: 14 AN XY: 74484

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00393

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000453

Asia WGS AF: 0.00144 AC: 5 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Progressive sclerosing poliodystrophy Benign:2

Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 31, 2024	- -
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.659+11G>T (NP_002684.1:p.=) [GRCH38: NC_000015.10:g.89333085C>A] variant in POLG gene is interpretated to be a Benign based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. BS1:The minor allele frequency of this allele is high for Mitochondrial DNA depletion syndrome 4A (Alpers type). BS2:Observation of the variant in controls is inconsistent with penetrance of Mitochondrial DNA depletion syndrome 4A (Alpers type). Based on the evidence criteria codes applied, the variant is suggested to be Benign. -

not specified Benign:1

Benign, criteria provided, single submitter

clinical testing

GeneDx

Sep 18, 2014

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.64
CADD	Benign	1.4
DANN	Benign	0.84
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs3087379; hg19: chr15-89876316;