NM_002693.3:c.3216C>G

Variant names:

• chr15-89318988-G-C
• rs146936870
• NM_002693.3:c.3216C>G

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_Strong BP6 BP7

The NM_002693.3(POLG):​c.3216C>G​(p.Thr1072Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000663 in 1,614,010 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 Conflicting classifications of pathogenicity (no stars). The gene POLG is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: 𝑓 0.000072 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000066 (0 hom.)
• Consequence: POLG NM_002693.3 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:6
• Conservation: PhyloP100: 0.572
• 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: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• mitochondrial DNA depletion syndrome 4a

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

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, 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

Specifications for POLG are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Likely_benign. The variant received -6 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.56).
• BP6: Variant 15-89318988-G-C is Benign according to our data. Variant chr15-89318988-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 138757.
• BP7: Synonymous conserved (PhyloP=0.572 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002693.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POLG	NM_002693.3	MANE Select	c.3216C>G	p.Thr1072Thr	synonymous	Exon 20 of 23	NP_002684.1	P54098
	POLG	NM_001126131.2		c.3216C>G	p.Thr1072Thr	synonymous	Exon 20 of 23	NP_001119603.1	P54098

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	POLG	ENST00000268124.11	TSL:1 MANE Select	c.3216C>G	p.Thr1072Thr	synonymous	Exon 20 of 23	ENSP00000268124.5	P54098
	POLG	ENST00000442287.6	TSL:1	c.3216C>G	p.Thr1072Thr	synonymous	Exon 20 of 23	ENSP00000399851.2	P54098
	POLG	ENST00000636937.2	TSL:5	c.3216C>G	p.Thr1072Thr	synonymous	Exon 20 of 23	ENSP00000516154.1	P54098

Frequencies

GnomAD3 genomes AF: 0.0000723 AC: 11 AN: 152128 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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: 0.000132

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000638 AC: 16 AN: 250896 AF XY: 0.0000590

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000706

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000657 AC: 96 AN: 1461882 Hom.: 0 Cov.: 32 AF XY: 0.0000756 AC XY: 55 AN XY: 727240

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000224 AC: 1 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.000128 AC: 11 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.000520 AC: 3 AN: 5768

European-Non Finnish (NFE) AF: 0.0000674 AC: 75 AN: 1112004

Other (OTH) AF: 0.0000993 AC: 6 AN: 60396

GnomAD4 genome AF: 0.0000723 AC: 11 AN: 152128 Hom.: 0 Cov.: 32 AF XY: 0.0000673 AC XY: 5 AN XY: 74306

African (AFR) AF: 0.00 AC: 0 AN: 41416

American (AMR) AF: 0.000131 AC: 2 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.000132 AC: 9 AN: 68032

Other (OTH) AF: 0.00 AC: 0 AN: 2082

Alfa AF: 0.0000670 Hom.: 0

Bravo AF: 0.0000982

EpiCase AF: 0.000218

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	1	not provided (2)
-	-	2	not specified (2)
-	-	2	Progressive sclerosing poliodystrophy (2)
-	-	1	Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.56
CADD	Benign	1.8
DANN	Benign	0.61
PhyloP100		0.57

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: rs146936870; hg19: chr15-89862219; COSMIC: COSV51525836; COSMIC: COSV51525836;