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rs113994095

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1PM5PP5_Very_Strong

The NM_002693(POLG):c.1399G>A(p.Ala467Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000657 in 152254 control chromosomes in the gnomAD Genomes database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A467D) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.00066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00051 ( 0 hom. )

Consequence

POLG
NM_002693 missense

Scores

6
10
2

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:44O:2

Conservation

PhyloP100: 7.47

Links

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PM1
?
In a helix (size 33) in uniprot entity DPOG1_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_002693
PM5
?
Other missense variant is known to change same aminoacid residue: Variant chr15-89327200-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2072863. Status of the report is criteria_provided_single_submitter, 1 stars.
PP5
?
Variant 15:89327201-C>T is Pathogenic according to our data. Variant chr15-89327201-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 13496. Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr15-89327201-C-T is described in Lovd as [Pathogenic]. Variant chr15-89327201-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
POLGNM_002693.3 linkuse as main transcriptc.1399G>A p.Ala467Thr missense_variant 7/23 ENST00000268124.11
POLGNM_001126131.2 linkuse as main transcriptc.1399G>A p.Ala467Thr missense_variant 7/23

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
POLGENST00000268124.11 linkuse as main transcriptc.1399G>A p.Ala467Thr missense_variant 7/231 NM_002693.3 P1

Frequencies

GnomAD3 genomes
AF:
0.000657
AC:
100
AN:
152254
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000169
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000188
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00131
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000513
AC:
129
AN:
251484
Hom.:
0
AF XY:
0.000522
AC XY:
71
AN XY:
135918
show subpopulations
Gnomad AFR exome
AF:
0.000369
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000924
Gnomad NFE exome
AF:
0.00102
Gnomad OTH exome
AF:
0.000489
GnomAD4 exome
AF:
0.00105
AC:
1537
AN:
1461884
Hom.:
0
AF XY:
0.00103
AC XY:
748
AN XY:
727244
show subpopulations
Gnomad4 AFR exome
AF:
0.000179
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.0000383
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.000187
Gnomad4 NFE exome
AF:
0.00133
Gnomad4 OTH exome
AF:
0.000646
Alfa
AF:
0.00112
Hom.:
1
Bravo
AF:
0.000627
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00156
AC:
6
ESP6500AA
AF:
0.000909
AC:
4
ESP6500EA
AF:
0.00140
AC:
12
ExAC
AF:
0.000519
AC:
63
Asia WGS
AF:
0.000289
AC:
2
AN:
3478
EpiCase
AF:
0.000872
EpiControl
AF:
0.00124

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:44Other:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:14
Pathogenic, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Pathogenic, criteria provided, single submitterclinical testingPerkinElmer GenomicsFeb 08, 2022- -
Pathogenic, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Dec 21, 2017- -
Pathogenic, no assertion criteria providedclinical testingLaboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)-- -
Pathogenic, no assertion criteria providedclinical testingJoint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+-- -
Pathogenic, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, Amsterdam University Medical Center-- -
Pathogenic, criteria provided, single submitterclinical testingMayo Clinic Laboratories, Mayo ClinicDec 21, 2021PS3, PS4_moderate, PM2, PP3, PP5 -
Pathogenic, criteria provided, single submitterclinical testingInstitute of Medical Genetics and Applied Genomics, University Hospital TübingenOct 23, 2020- -
Pathogenic, no assertion criteria providedclinical testingGenetic Services Laboratory, University of ChicagoSep 03, 2022DNA sequence analysis of the POLG gene demonstrated a sequence change, c.1399G>A, in exon 7 that results in an amino acid change, p.Ala467Thr. The p.Ala467Thr change affects a highly conserved amino acid residue located in a domain of the POLG protein that is known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Ala467Thr substitution. This pathogenic sequence change has previously been described as the most common POLG variant associated with autosomal recessive Alpers-Huttenlocher syndrome (PMID: 20301791). This sequence change has been associated with reduced enzyme activity (PMID: 20301791). This sequence change has been described in the gnomAD database with a frequency of 0.05% in the overall population (dbSNP rs113994095). These collective evidences indicate that this sequence change is pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingGeneDxNov 25, 2019Identified in individuals with autosomal recessive progressive external ophthalmoplegia (arPEO) and has subsequently been identified in patients with Alpers syndrome, sensory ataxic neuropathy dysarthria and ophthalmoparesis (SANDO), and other POLG-related disorders causing epilepsy, ataxia, neuropathy, hepatopathy, and/or myopathy (vanGoethem et al., 2001); Published functional studies demonstrate a damaging effect (Kasahara et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 22616202, 16368709, 11431686, 20837861, 21235791, 21686371, 22189570, 21515089, 22342071, 23448099, 22995991, 15917273, 21993618, 23212759, 18500570, 23430834, 24272679, 23783014, 20576279, 20691285, 20818383, 22931735, 22006280, 21647632, 25286830, 20138553, 21880868, 16024923, 26104464, 26735972, 27987238, 15122711, 15824347, 18783964, 19501198, 19766516, 28771251, 19813183, 19538466, 29588995, 18546343, 24725338, 29655203, 30167885, 30423451, 30369941, 27422324, 31980526, 31589614, 33473333) -
Pathogenic, criteria provided, single submitterclinical testingAiLife Diagnostics, AiLife DiagnosticsMar 17, 2022- -
Pathogenic, criteria provided, single submitterclinical testingAthena Diagnostics IncSep 07, 2022The frequency of this variant in the general population is consistent with pathogenicity ((Genome Aggregation Database (gnomAD), Cambridge, MA (URL: http://gnomad.broadinstitute.org)). This variant has been identified in multiple individuals with different autosomal recessive POLG-related disorders. Assessment of experimental evidence suggests this variant results in abnormal protein function. In an in vitro study, this variant abrogated polymerase activity, processivity, and exonuclease activity (PMID: 27987238). In multiple individuals, this variant has been seen with a single recessive pathogenic variant in the same gene, suggesting this variant may also be pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenSep 01, 2021- -
Pathogenic, no assertion criteria providedclinical testingDiagnostic Laboratory, Department of Genetics, University Medical Center Groningen-- -
Progressive sclerosing poliodystrophy Pathogenic:7
Pathogenic, criteria provided, single submitterclinical testingVictorian Clinical Genetics Services, Murdoch Childrens Research InstituteJul 22, 20200102 - Loss of function is a known mechanism of disease in this gene and is associated with POLG-related mitochondrial disorders. (I) 0108 - This gene is associated with both recessive and dominant disease. Variants in this gene predominantly cause recessive disease however, progressive external ophthalmoplegia can also be dominantly inherited (OMIM). (I) 0112 - Autosomal dominant progressive external ophthalmoplegia associated with this gene has incomplete penetrance (OMIM). (I) 0200 - Variant is predicted to result in a missense amino acid change from alanine to threonine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD <0.01 for a recessive condition (v2: 143 heterozygotes, 0 homozygotes). (SP) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0600 - Variant is located in the linker region (PMID: 16024923). (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This is one of the most reported variants predominantly in homozygous and compound heterozygous individuals with mitochondrial DNA depletion syndrome 4A (Alpers type) (ClinVar, PMID: 20301791). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Pathogenic, criteria provided, single submitterclinical testingUndiagnosed Diseases Network, NIHJan 03, 2018This is the most common pathogenic variant described in cases of Alpers-Huttenlocher syndrome (Mitochondrial DNA depletion syndrome 4A (Alpers type), MIM 203700), we have sparse records on the patient's phenotype (long deceased), but it seems a very reasonable clinical fit, albeit perhaps somewhat late onset (age 11). -
Pathogenic, no assertion criteria providedliterature onlyOMIMFeb 11, 2011- -
Pathogenic, criteria provided, single submitterclinical testingWong Mito Lab, Molecular and Human Genetics, Baylor College of MedicineOct 01, 2018The NM_002693.2:c.1399G>A (NP_002684.1:p.Ala467Thr) [GRCH38: NC_000015.10:g.89327201C>T] variant in POLG gene is interpretated to be a Pathogenic based on ACMG guidelines (PMID: 25741868). This variant meets the following evidence codes reported in the ACMG-guideline. PS3:Well established functional studies show a deleterious effect on POLG. PS4:Prevalence of variant in affecteds statistically increased over controls. PM3:Detected in trans with a pathogenic variant for Mitochondrial DNA depletion syndrome 4A (Alpers type) which is a recessive disorder. PP1:This variant is co-segregated with Mitochondrial DNA depletion syndrome 4A (Alpers type) in multiple affected family members. PP4:Patient's phenotype or family history is highly specific for POLG. PP5:Reputable source(s) suggest that the variant is pathogenic. Based on the evidence criteria codes applied, the variant is suggested to be Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingMGZ Medical Genetics CenterAug 29, 2022- -
Pathogenic, criteria provided, single submitterclinical testingInvitaeNov 03, 2022This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 467 of the POLG protein (p.Ala467Thr). This variant is present in population databases (rs113994095, gnomAD 0.09%), and has an allele count higher than expected for a pathogenic variant. This missense change has been observed in individual(s) with autosomal recessive POLG-related disorders, Alpers-Huttenlocher syndrome, autosomal recessive progressive external ophthalmoplegia, sensory ataxic neuropathy, dysarthria and ophthalmoplegia (SANDO), and other POLG-related disorders causing epilepsy, ataxia, neuropathy, hepatopathy, and myopathy (PMID: 11431686, 15122711, 15917273, 20691285, 25286830, 26735972). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 13496). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on POLG protein function. Experimental studies have shown that this missense change affects POLG function (PMID: 15917273, 16024923). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingEquipe Genetique des Anomalies du Developpement, Université de Bourgogne-- -
Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 1 Pathogenic:3
Pathogenic, no assertion criteria providedliterature onlyOMIMFeb 11, 2011- -
Pathogenic, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineApr 24, 2014The Ala467Thr variant in POLG has been reported in >20 individuals with mitochondrial disease in both the homozygous and compound heterozygous states, with symptoms ranging from progressive external ophthalmoplegia to intractable epilepsy to Alpers syndrome (van Goethem 2001, van Goethem 2004, Ferrari 2005, Winterthun 2005, Lax 2012, Scalais 2012, Uusimaa 2012). This variant has also been identified in 0.14% (12/8598) of European American chromosomes and 0.09% (4/4400) of African American chromosomes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/. In vitro functional studies have shown that the Ala467Thr variant leads to loss of wild-type activity and binding affinity (Chan 2005, Luoma 2005). In summary, this variant meets our criteria to be classified as pathogenic (http://pcpgm.partners.org/LMM). -
Pathogenic, criteria provided, single submitterclinical testingMolecular Genetics, Royal Melbourne HospitalApr 23, 2020This sequence change is predicted to replace alanine with threonine at codon 467 of the POLG protein (p.Ala467Thr). The alanine residue is highly conserved (100 vertebrates, UCSC), and is located in a helix within the linker region. There is a small physicochemical difference between alanine and threonine. The variant is present in a large population cohort at a frequency of 0.051%] (rs113994095, 143/282,888 alleles, 0 homozygotes in gnomAD v2.1). The variant is the most commonly reported POLG variant. It has been identified in the homozygous state and compound heterozygous with a second pathogenic allele in various POLG-related disorders, and segregates with disease in multiple families (PMID: 11431686, 15122711, 15917273, 21880868 - PM3_VeryStrong, PP1_Moderate). In vitro assays show reduced enzyme activity and DNA binding for the variant (PMID: 15917273, 16024923 - PS3_Supporting). Multiple lines of computational evidence predict a deleterious effect for the missense substitution (6/7 algorithms - PP3). Based on the classification scheme RMH ACMG Guidelines v1.2.1, this variant is classified as PATHOGENIC . Following criteria are met: PM3_VeryStrong, PP1_Moderate, PS3_Supporting, PP3. -
Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis Pathogenic:3
Pathogenic, no assertion criteria providedliterature onlyOMIMFeb 11, 2011- -
Pathogenic, criteria provided, single submitterclinical testingInstitute of Human Genetics, Klinikum rechts der IsarNov 08, 2018- -
Pathogenic, criteria provided, single submitterclinical testingLaboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert EinsteinAug 04, 2022ACMG classification criteria: PS4 strong, PM3 very strong, PP1 strong, PP3 supporting, PP4 -
Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 1 Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingBaylor GeneticsMar 26, 2020This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. Both variants have been previously reported as disease-causing [PMID 19578034 etc.] -
Pathogenic, criteria provided, single submitterclinical testingCourtagen Diagnostics Laboratory, Courtagen Life SciencesDec 16, 2013- -
POLG-Related Spectrum Disorders Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpDec 06, 2022Variant summary: POLG c.1399G>A (p.Ala467Thr) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00051 in 251484 control chromosomes (gnomAD). c.1399G>A has been reported in the literature as a biallelic genotype in multiple individuals affected with POLG-Related Spectrum Disorders (e.g. Van Goethem_2003, Luoma_2005, Winterthun_2005, Kollberg_2006). These data indicate that the variant is very likely to be associated with disease. Functional analysis using purified recombinant protein showed the variant had reduced binding affinity to DNA and reduced DNA synthesis activity (14% and 18% of controls, respectively. Luoma_2005). Twenty-five ClinVar submitters have assessed the variant since 2014: all classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJun 14, 2016- -
POLG-related disorders Pathogenic:1Other:1
not provided, no assertion providedphenotyping onlyGenomeConnect, ClinGen-GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Pathogenic, criteria provided, single submitterresearchUNC Molecular Genetics Laboratory, University of North Carolina at Chapel Hill-The POLG c.1399G>A (p.A467T) variant is the most common POLG variant associated with autosomal recessive Alpers-Huttenlocher syndrome (characterized by seizures, loss of mental and movement abilities, and liver disease PMID: 20301791). -
Mitochondrial disease Pathogenic:1Other:1
not provided, no assertion providedliterature onlyGeneReviews-- -
Pathogenic, no assertion criteria providedclinical testingWellcome Centre for Mitochondrial Research, Newcastle UniversityApr 07, 2017- -
Neurodevelopmental delay Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingCentre de Biologie Pathologie Génétique, Centre Hospitalier Universitaire de Lille-- -
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 Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsDec 28, 2021- -
Inborn genetic diseases Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingAmbry GeneticsJul 16, 2018The p.A467T pathogenic mutation (also known as c.1399G>A), located in coding exon 6 of the POLG gene, results from a G to A substitution at nucleotide position 1399. The alanine at codon 467 is replaced by threonine, an amino acid with similar properties. This mutation is the most common recessive pathogenic mutation found in POLG and accounts for 31% of all mutant alleles (Tang, et al. S, J. Med. Genet. 2011; 48(10):669-81). This mutation has been identified in both compound heterozygous and homozygous states in many individuals presenting with a wide range of mitochondrial disorders, including but not limited to: Alpers syndrome, juvenile spinocerebellar ataxia-epilepsy syndrome, progressive external ophthalmoplegia, and other POLG-related disorders including ataxia, neuropathy, epilepsy, hepatopathy, and myopathy (Chan SS et al. J. Biol. Chem. 2005; 280(36):31341-6; Tang SJ et al. J. Med. Genet. 2011;48(10):669-81; Van Goethem Get al. Nat. Genet. 2001;28(3):211-2; Van Goethem G et al. Neuromuscul. Disord. 2003;13(2):133-42; Luoma PT et al. Hum. Mol. Genet. 2005;14(14):1907-20). In addition, this mutation is located in the polymerase domain (also known as the linker region) of POLG, has been found to result in 4-20% of wild-type DNA polymerase activity and fails to interact with the catalytic accessory subunit resulting in compromised catalytic activity (Chan SS et al. J. Biol. Chem. 2005; 280(36):31341-6). Of note, in one family, this mutation caused a mild dominant manifestation of late onset ptosis which required operative correction in three affected individuals (Luoma PT et al. Hum. Mol. Genet. 2005; 14(14):1907-20). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
Hereditary spastic paraplegia Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingGenome Diagnostics Laboratory, The Hospital for Sick ChildrenMay 01, 2020- -
POLG-related condition Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingUndiagnosed Diseases Network, NIHJun 27, 2018Submitting this as a novel interpretation as this patient's phenotype does not fit any of the POLG-associated conditions listed in OMIM. This is a different observation than SCV000837701.1 where we observed this variant in a compound heterozygous state with another POLG variant and the patient fit the POLG-related conditions listed in OMIM. -
Mitochondrial DNA depletion syndrome 4b Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingCentre for Mendelian Genomics, University Medical Centre LjubljanaMay 07, 2019This variant was classified as: Pathogenic. The following ACMG criteria were applied in classifying this variant: PS1,PS3,PM2,PM3,PP3. -
Spinocerebellar ataxia with epilepsy Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMFeb 11, 2011- -
Progressive sclerosing poliodystrophy;C1843851:Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis;C3150914:Mitochondrial DNA depletion syndrome 4b;C4225153:Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 1 Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingGreenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic CenterAug 23, 2021PS3, PS4, PM1, PM3, PP3 -
Tip-toe gait Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingPractice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice PomarinoNov 08, 2018- -
Progressive sclerosing poliodystrophy;C3150914:Mitochondrial DNA depletion syndrome 4b Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingBaylor Genetics-- -
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 Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingRady Children's Institute for Genomic Medicine, Rady Children's Hospital San DiegoJul 21, 2020This variant has been previously reported as a homozygous and a compound heterozygous change in multiple patients and reported to segregate in several families affected by autosomal recessive POLG-related disorders including Alpers-Huttenlocher syndrome (AHS), progressive ataxic neuropathy, Parieto-occipital lobe epilepsy and Mitochondrial neurogastrointestinal encephalomyopathy-like syndrome (PMID: 11431686, 26735972, 15122711, 25286830, 20691285, 15917273). This is the most common AHS-causing variant in the POLG gene. Functional characterization indicates that the p.Ala467Thr variant, which is located near the exonuclease domain in the early linker region of the protein, severely reduces DNA polymerase gamma activity (down to 4% of wild type activity) by compromising the catalytic efficiency of the POLG protein (PMID: 16024923, 15917273). In addition, p.Ala467Thr fails to associate with the POLG2 accessory subunit, which leads to stalling at the replication fork and depletion of mtDNA over time (PMID: 16024923, 27987238, 16368709). The p.Ala467Thr variant is present in the heterozygous state in the gnomAD population database at a frequency of 0.051% (143/282888) and thus is presumed to be rare. In silico analyses support a deleterious effect of the c.1399G>A (p.Ala467Thr) variant on protein function. Based on the available evidence, the c.1399G>A (p.Ala467Thr) variant is classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.77
BayesDel_addAF
Uncertain
0.15
D
BayesDel_noAF
Pathogenic
0.41
Cadd
Pathogenic
26
Dann
Pathogenic
1.0
DEOGEN2
Pathogenic
0.81
D;D
Eigen
Uncertain
0.66
Eigen_PC
Uncertain
0.64
FATHMM_MKL
Pathogenic
0.99
D
M_CAP
Uncertain
0.22
D
MetaRNN
Uncertain
0.73
D;D
MetaSVM
Uncertain
0.78
D
MutationAssessor
Benign
1.9
M;M
MutationTaster
Benign
1.0
A;A
PrimateAI
Uncertain
0.65
T
PROVEAN
Uncertain
-3.3
D;D
REVEL
Pathogenic
0.88
Sift
Uncertain
0.0030
D;D
Sift4G
Uncertain
0.055
T;T
Polyphen
1.0
D;D
Vest4
0.92
MVP
0.98
MPC
0.65
ClinPred
0.16
T
GERP RS
5.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.77
gMVP
0.68

Splicing

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs113994095; hg19: chr15-89870432;