15-89333615-T-TGCTGCTGCTGCTGCC

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_002693.3(POLG):​c.125_139dupGGCAGCAGCAGCAGC​(p.Arg42_Gln46dup) variant causes a conservative inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000132 in 152,076 control chromosomes in the GnomAD database, with no homozygous occurrence. It is difficult to determine the true allele frequency of this variant because it is of type INS_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. Q47Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000012 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

POLG
NM_002693.3 conservative_inframe_insertion

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1

Conservation

PhyloP100: 0.638

Publications

0 publications found
Variant links:
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]

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

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.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
POLG
NM_002693.3
MANE Select
c.125_139dupGGCAGCAGCAGCAGCp.Arg42_Gln46dup
conservative_inframe_insertion
Exon 2 of 23NP_002684.1P54098
POLGARF
NM_001430120.1
MANE Select
c.180_194dupGGCAGCAGCAGCAGCp.Ala61_Ala65dup
disruptive_inframe_insertion
Exon 1 of 2NP_001417049.1A0A3B3IS91
POLG
NM_001126131.2
c.125_139dupGGCAGCAGCAGCAGCp.Arg42_Gln46dup
conservative_inframe_insertion
Exon 2 of 23NP_001119603.1P54098

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
POLG
ENST00000268124.11
TSL:1 MANE Select
c.125_139dupGGCAGCAGCAGCAGCp.Arg42_Gln46dup
conservative_inframe_insertion
Exon 2 of 23ENSP00000268124.5P54098
POLG
ENST00000442287.6
TSL:1
c.125_139dupGGCAGCAGCAGCAGCp.Arg42_Gln46dup
conservative_inframe_insertion
Exon 2 of 23ENSP00000399851.2P54098
POLGARF
ENST00000706918.1
MANE Select
c.180_194dupGGCAGCAGCAGCAGCp.Ala61_Ala65dup
disruptive_inframe_insertion
Exon 1 of 2ENSP00000516626.1A0A3B3IS91

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152076
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000223
AC:
5
AN:
224210
AF XY:
0.0000322
show subpopulations
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:
0.0000503
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.0000124
AC:
18
AN:
1448696
Hom.:
0
Cov.:
32
AF XY:
0.0000153
AC XY:
11
AN XY:
720504
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33258
American (AMR)
AF:
0.00
AC:
0
AN:
43824
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25950
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39360
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85622
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47182
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5732
European-Non Finnish (NFE)
AF:
0.0000144
AC:
16
AN:
1107920
Other (OTH)
AF:
0.0000334
AC:
2
AN:
59848
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.0000000946815), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.397
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
152076
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74304
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41418
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67962
Other (OTH)
AF:
0.00
AC:
0
AN:
2082
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0

ClinVar

ClinVar submissions
Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
2
-
Progressive sclerosing poliodystrophy (2)
-
1
-
Inborn genetic diseases (1)
-
1
-
not provided (1)
-
-
1
not specified (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
PhyloP100
0.64
Mutation Taster
=85/15
polymorphism

Splicing

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

Publications

Other links and lift over

dbSNP: rs780010436; hg19: chr15-89876846; API