15-89323966-C-T

Variant names:

• chr15-89323966-C-T
• rs2307439
• NM_002693.3:c.2071-65G>A

Variant summary

Our verdict is Benign. The variant received -12 ACMG points: 0P and 12B. BP4_Strong BS1 BS2

The NM_002693.3(POLG):​c.2071-65G>A variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0033 in 1,536,812 control chromosomes in the GnomAD database, including 50 homozygotes. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. The gene POLG is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: 𝑓 0.0032 (9 hom., cov: 33)
  • Exomes 𝑓: 0.0033 (41 hom.)
• Consequence: POLG NM_002693.3 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.467
• Publications: 6 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, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• mitochondrial DNA depletion syndrome 4a

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

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

Our verdict: Benign. The variant received -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BS1: Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.00324 (494/152346) while in subpopulation EAS AF = 0.0494 (256/5184). AF 95% confidence interval is 0.0444. There are 9 homozygotes in GnomAd4. There are 245 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.
• BS2: High Homozygotes in GnomAd4 at 9 AR,AD gene

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.2071-65G>A		intron	N/A	NP_002684.1	P54098
	POLG	NM_001126131.2		c.2071-65G>A		intron	N/A	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.2071-65G>A		intron	N/A	ENSP00000268124.5	P54098
	POLG	ENST00000442287.6	TSL:1	c.2071-65G>A		intron	N/A	ENSP00000399851.2	P54098
	POLG	ENST00000636937.2	TSL:5	c.2071-65G>A		intron	N/A	ENSP00000516154.1	P54098

Frequencies

GnomAD3 genomes AF: 0.00324 AC: 493 AN: 152228 Hom.: 9 Cov.: 33

Gnomad AFR AF: 0.000844

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000589

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.0491

Gnomad SAS AF: 0.00414

Gnomad FIN AF: 0.00386

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00182

Gnomad OTH AF: 0.00430

GnomAD4 exome AF: 0.00331 AC: 4576 AN: 1384466 Hom.: 41 Cov.: 23 AF XY: 0.00328 AC XY: 2270 AN XY: 692798

African (AFR) AF: 0.000907 AC: 29 AN: 31968

American (AMR) AF: 0.000382 AC: 17 AN: 44530

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25610

East Asian (EAS) AF: 0.0466 AC: 1832 AN: 39290

South Asian (SAS) AF: 0.00416 AC: 352 AN: 84664

European-Finnish (FIN) AF: 0.00340 AC: 181 AN: 53234

Middle Eastern (MID) AF: 0.000533 AC: 3 AN: 5624

European-Non Finnish (NFE) AF: 0.00180 AC: 1879 AN: 1041764

Other (OTH) AF: 0.00490 AC: 283 AN: 57782

GnomAD4 genome AF: 0.00324 AC: 494 AN: 152346 Hom.: 9 Cov.: 33 AF XY: 0.00329 AC XY: 245 AN XY: 74498

African (AFR) AF: 0.000842 AC: 35 AN: 41578

American (AMR) AF: 0.000588 AC: 9 AN: 15300

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

East Asian (EAS) AF: 0.0494 AC: 256 AN: 5184

South Asian (SAS) AF: 0.00414 AC: 20 AN: 4830

European-Finnish (FIN) AF: 0.00386 AC: 41 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00182 AC: 124 AN: 68036

Other (OTH) AF: 0.00425 AC: 9 AN: 2116

Alfa AF: 0.00143 Hom.: 0

Bravo AF: 0.00288

Asia WGS AF: 0.0300 AC: 105 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	9.8
DANN	Benign	0.81
PhyloP100		-0.47
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs2307439;

hg19: chr15-89867197;

COSMIC: COSV51521773;

COSMIC: COSV51521773;