rs2307440
Variant summary
Our verdict is Uncertain significance. Variant got 0 ACMG points: 0P and 0B.
The NM_002693.3(POLG):c.3436C>T(p.Arg1146Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000149 in 1,614,046 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_002693.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000151 AC: 23AN: 152176Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000187 AC: 47AN: 251396Hom.: 0 AF XY: 0.000191 AC XY: 26AN XY: 135880
GnomAD4 exome AF: 0.000149 AC: 218AN: 1461752Hom.: 0 Cov.: 32 AF XY: 0.000151 AC XY: 110AN XY: 727172
GnomAD4 genome AF: 0.000151 AC: 23AN: 152294Hom.: 0 Cov.: 32 AF XY: 0.000148 AC XY: 11AN XY: 74466
ClinVar
Submissions by phenotype
Progressive sclerosing poliodystrophy Uncertain:3Benign:1
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The NM_002693.2:c.3436C>T (NP_002684.1:p.Arg1146Cys) [GRCH38: NC_000015.10:g.89318587G>A] variant in POLG gene is interpretated to be a Benign based on ACMG guidelines (PMID: 25741868). This variant has been reported in PMID:16401742 . This variant meets the following evidence codes reported in the ACMG-guideline. BS1:The minor allele frequency of this allele is high for Mitochondrial DNA depletion syndrome 4A (Alpers type). BS2:Observation of the variant in controls is inconsistent with penetrance of Mitochondrial DNA depletion syndrome 4A (Alpers type). Based on the evidence criteria codes applied, the variant is suggested to be Benign. -
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 1146 of the POLG protein (p.Arg1146Cys). This variant is present in population databases (rs2307440, gnomAD 0.03%). This missense change has been observed in individual(s) with autosomal dominant progressive external ophthalmoplegia and/or mitochondrial disease (PMID: 16401742, 20843780, 21880868, 30838265). ClinVar contains an entry for this variant (Variation ID: 21313). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt POLG protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects POLG function (PMID: 25462018). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. This variant has been previously reported in patients with mitochondrial disorders [PMID 16401742] -
not provided Uncertain:3
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). Assessment of experimental analysis yielded inconclusive results regarding the impact of this variant on protein function. Functional analysis of the yeast homologue of this variant indicates that it is damaging to protein function; however, these results have not been confirmed in vitro in human cell types. -
Identified heterozygous in an adult with diplopia, dysarthria, and dysphagia, loss skills, cerebellar dysarthria, severe horizontal and vertical external ophthalmoparesis, esotropia, slight left ptosis, and asymmetric facial muscle weakness. The proband's mother with strabismus was also heterozygous (PMID: 30838265); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 21880868, 20843780, 15913923, 25462018, 19275594, 31996268, 34828412, 16401742, 30838265, 34803902, 32613234) -
POLG: PP3 -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at