rs886051522

Variant names:

• chr15-89318925-A-T
• rs886051522
• NM_002693.3:c.3273+6T>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BP6

The NM_002693.3(POLG):​c.3273+6T>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,804 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. 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: not found (cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: POLG NM_002693.3 splice_region, intron
• Scores: Splicing: ADA: 0.01080
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 0.393
• Publications: 0 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 -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BP6: Variant 15-89318925-A-T is Benign according to our data. Variant chr15-89318925-A-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 317324.

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.3273+6T>A		splice_region intron	N/A	NP_002684.1	P54098
	POLG	NM_001126131.2		c.3273+6T>A		splice_region 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.3273+6T>A		splice_region intron	N/A	ENSP00000268124.5	P54098
	POLG	ENST00000442287.6	TSL:1	c.3273+6T>A		splice_region intron	N/A	ENSP00000399851.2	P54098
	POLG	ENST00000636937.2	TSL:5	c.3273+6T>A		splice_region intron	N/A	ENSP00000516154.1	P54098

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000797 AC: 2 AN: 250908 AF XY: 0.00000737

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000177

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000821 AC: 12 AN: 1461804 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 727210

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 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: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53386

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000108 AC: 12 AN: 1111960

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000468 Hom.: 0

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	1	Progressive sclerosing poliodystrophy (2)
-	1	-	POLG-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	8.4
DANN	Benign	0.85
PhyloP100		0.39

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.011
dbscSNV1_RF	Benign	0.23
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: rs886051522; hg19: chr15-89862156;