rs775517153

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 1P and 0B. PP3

The NM_002693.3(POLG):​c.3680C>A​(p.Thr1227Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,613,896 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

POLG
NM_002693.3 missense

Scores

7
10
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 9.56
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]
FANCI (HGNC:25568): (FA complementation group I) The Fanconi anemia complementation group (FANC) currently includes FANCA, FANCB, FANCC, FANCD1 (also called BRCA2), FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ (also called BRIP1), FANCL, FANCM and FANCN (also called PALB2). The previously defined group FANCH is the same as FANCA. Fanconi anemia is a genetically heterogeneous recessive disorder characterized by cytogenetic instability, hypersensitivity to DNA crosslinking agents, increased chromosomal breakage, and defective DNA repair. The members of the Fanconi anemia complementation group do not share sequence similarity; they are related by their assembly into a common nuclear protein complex. This gene encodes the protein for complementation group I. Alternative splicing results in two transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.801

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
POLGNM_002693.3 linkuse as main transcriptc.3680C>A p.Thr1227Asn missense_variant 23/23 ENST00000268124.11 NP_002684.1
FANCINM_001113378.2 linkuse as main transcriptc.*332G>T 3_prime_UTR_variant 38/38 ENST00000310775.12 NP_001106849.1
POLGARFNM_001406557.1 linkuse as main transcriptc.*2952C>A 3_prime_UTR_variant 23/23 NP_001393486.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
POLGENST00000268124.11 linkuse as main transcriptc.3680C>A p.Thr1227Asn missense_variant 23/231 NM_002693.3 ENSP00000268124 P1
FANCIENST00000310775.12 linkuse as main transcriptc.*332G>T 3_prime_UTR_variant 38/381 NM_001113378.2 ENSP00000310842 P1Q9NVI1-3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251304
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135870
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000178
AC:
26
AN:
1461704
Hom.:
0
Cov.:
30
AF XY:
0.0000179
AC XY:
13
AN XY:
727168
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000234
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74344
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000772
Hom.:
0
Bravo
AF:
0.00000378
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Jul 24, 2018- -
Uncertain significance, criteria provided, single submitterclinical testingMayo Clinic Laboratories, Mayo ClinicJun 28, 2021- -
Progressive sclerosing poliodystrophy Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJul 06, 2022This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 1227 of the POLG protein (p.Thr1227Asn). This variant is present in population databases (rs775517153, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with POLG-related conditions. ClinVar contains an entry for this variant (Variation ID: 598136). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -
Uncertain significance, criteria provided, single submitterclinical testingWong Mito Lab, Molecular and Human Genetics, Baylor College of MedicineOct 01, 2018The NM_002693.2:c.3680C>A (NP_002684.1:p.Thr1227Asn) [GRCH38: NC_000015.10:g.89316791G>T] variant in FANCI 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. BP4:Computational evidence/predictors indicate no impact on the FANCI structure, function, or protein-protein interaction. Based on the evidence criteria codes applied, the variant is suggested to be Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.87
BayesDel_addAF
Pathogenic
0.25
D
BayesDel_noAF
Uncertain
0.12
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.51
D;D
Eigen
Pathogenic
0.89
Eigen_PC
Pathogenic
0.90
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.89
.;D
M_CAP
Uncertain
0.20
D
MetaRNN
Pathogenic
0.80
D;D
MetaSVM
Pathogenic
0.98
D
MutationAssessor
Uncertain
2.3
M;M
MutationTaster
Benign
1.0
D;D;D;D
PrimateAI
Uncertain
0.74
T
PROVEAN
Benign
-2.0
N;N
REVEL
Uncertain
0.49
Sift
Uncertain
0.0080
D;D
Sift4G
Uncertain
0.012
D;D
Polyphen
1.0
D;D
Vest4
0.73
MutPred
0.19
Gain of catalytic residue at T1227 (P = 0.0708);Gain of catalytic residue at T1227 (P = 0.0708);
MVP
0.99
MPC
0.70
ClinPred
0.91
D
GERP RS
6.0
Varity_R
0.57
gMVP
0.85

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
Details are displayed if max score is > 0.2

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: rs775517153; hg19: chr15-89860022; API