rs551708243
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3
The NM_002693.3(POLG):c.3098C>T(p.Ala1033Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00022 in 1,614,122 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/24 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1033K) has been classified as Uncertain significance.
Frequency
Consequence
NM_002693.3 missense
Scores
Clinical Significance
Conservation
Publications
- progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
- mitochondrial DNA depletion syndrome 4aInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Orphanet, G2P
- sensory ataxic neuropathy, dysarthria, and ophthalmoparesisInheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Ambry Genetics, Orphanet, G2P
- autosomal dominant progressive external ophthalmoplegiaInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- autosomal recessive progressive external ophthalmoplegiaInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- mitochondrial neurogastrointestinal encephalomyopathyInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- recessive mitochondrial ataxia syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- spinocerebellar ataxia with epilepsyInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- Leigh syndromeInheritance: AR Classification: LIMITED Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| POLG | ENST00000268124.11 | c.3098C>T | p.Ala1033Val | missense_variant | Exon 19 of 23 | 1 | NM_002693.3 | ENSP00000268124.5 |
Frequencies
GnomAD3 genomes AF: 0.000342 AC: 52AN: 152118Hom.: 1 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000255 AC: 64AN: 251460 AF XY: 0.000243 show subpopulations
GnomAD4 exome AF: 0.000207 AC: 303AN: 1461886Hom.: 0 Cov.: 34 AF XY: 0.000202 AC XY: 147AN XY: 727244 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.000342 AC: 52AN: 152236Hom.: 1 Cov.: 32 AF XY: 0.000443 AC XY: 33AN XY: 74442 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:4Benign:1
This variant is associated with the following publications: (PMID: 21880868, 30290626) -
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Available data are insufficient to determine the clinical significance of the variant at this time. The frequency of this variant in the general population is uninformative in assessment of its pathogenicity. (http://gnomad.broadinstitute.org) Computational tools predict that this variant is not damaging. -
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Progressive sclerosing poliodystrophy Uncertain:1Benign:1
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The NM_002693.2:c.3098C>T (NP_002684.1:p.Ala1033Val) [GRCH38: NC_000015.10:g.89319234G>A] variant in POLG gene is interpretated to be a Uncertain Significance based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. BS2:Observation of the variant in controls is inconsistent with penetrance of Mitochondrial DNA depletion syndrome 4A (Alpers type). BP4:Computational evidence/predictors indicate no impact on the POLG structure, function, or protein-protein interaction. PP3:Computational evidence/predictors indicate the variant has deleterious effect on POLG structure, function, or protein-protein interaction. Based on the evidence criteria codes applied, the variant is suggested to be Uncertain Significance. -
Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 1 Uncertain:1
This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
Progressive sclerosing poliodystrophy;C1834846:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1;C1843851:Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis;C3150914:Mitochondrial DNA depletion syndrome 4b;C4225153:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 1;C4551995:Mitochondrial DNA depletion syndrome 1 Uncertain:1
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POLG-Related Spectrum Disorders Uncertain:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Inborn genetic diseases Uncertain:1
The c.3098C>T (p.A1033V) alteration is located in exon 19 (coding exon 18) of the POLG gene. This alteration results from a C to T substitution at nucleotide position 3098, causing the alanine (A) at amino acid position 1033 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1;C1843851:Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis;C3150914:Mitochondrial DNA depletion syndrome 4b;C4225153:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 1;C4551995:Mitochondrial DNA depletion syndrome 1 Uncertain:1
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POLG-related disorder Uncertain:1
The POLG c.3098C>T variant is predicted to result in the amino acid substitution p.Ala1033Val. This variant has been reported in the compound heterozygous state along with a second variant in this gene in a individual with hypotonia, low set ears, and bilateral clubfeet (AlJabri et al. 2018. PubMed ID: 30290626) and found in the heterozygous condition another individual with encephalopathy, seizure, and abnormal MRI (Table S2, Tang et al. 2011. PubMed ID: 21880868). This variant is reported in 0.13% of alleles in individuals of Ashkenazi Jewish descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at