6-30915985-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP5

The NM_020442.6(VARS2):​c.511C>T​(p.Arg171Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000242 in 1,613,864 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R171Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000099 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

VARS2
NM_020442.6 missense

Scores

8
5
6

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:2

Conservation

PhyloP100: 0.856

Publications

5 publications found
Variant links:
Genes affected
VARS2 (HGNC:21642): (valyl-tRNA synthetase 2, mitochondrial) This gene encodes a mitochondrial aminoacyl-tRNA synthetase, which catalyzes the attachment of valine to tRNA(Val) for mitochondrial translation. Mutations in this gene cause combined oxidative phosphorylation deficiency-20, and are also associated with early-onset mitochondrial encephalopathies. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Aug 2014]
VARS2 Gene-Disease associations (from GenCC):
  • mitochondrial disease
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • combined oxidative phosphorylation defect type 20
    Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PP5
Variant 6-30915985-C-T is Pathogenic according to our data. Variant chr6-30915985-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 488636.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
VARS2NM_020442.6 linkc.511C>T p.Arg171Trp missense_variant Exon 6 of 30 ENST00000676266.1 NP_065175.4 Q5ST30-1B4E0K6B4DG77
VARS2NM_001167734.2 linkc.601C>T p.Arg201Trp missense_variant Exon 6 of 30 NP_001161206.1 Q5ST30-4A0A1U9X9B3
VARS2NM_001167733.3 linkc.91C>T p.Arg31Trp missense_variant Exon 5 of 29 NP_001161205.1 Q5ST30-3B4E0K6

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
VARS2ENST00000676266.1 linkc.511C>T p.Arg171Trp missense_variant Exon 6 of 30 NM_020442.6 ENSP00000502585.1 Q5ST30-1

Frequencies

GnomAD3 genomes
AF:
0.0000986
AC:
15
AN:
152142
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000362
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000318
AC:
8
AN:
251272
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.000308
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:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000164
AC:
24
AN:
1461722
Hom.:
0
Cov.:
32
AF XY:
0.0000165
AC XY:
12
AN XY:
727146
show subpopulations
African (AFR)
AF:
0.000418
AC:
14
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53404
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000630
AC:
7
AN:
1111874
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60378
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.463
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:
0.0000986
AC:
15
AN:
152142
Hom.:
0
Cov.:
32
AF XY:
0.0000942
AC XY:
7
AN XY:
74324
show subpopulations
African (AFR)
AF:
0.000362
AC:
15
AN:
41428
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.495
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000928
Hom.:
0
Bravo
AF:
0.000128
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:3Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Combined oxidative phosphorylation defect type 20 Pathogenic:2
Nov 16, 2017
Institute of Human Genetics Munich, TUM University Hospital
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 13, 2020
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Inborn genetic diseases Pathogenic:1
Aug 22, 2017
Ambry Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Apr 21, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: VARS2 c.511C>T (p.Arg171Trp) 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 2.4e-05 in 1606868 control chromosomes, predominantly at a frequency of 0.00039 within the African or African-American subpopulation in the gnomAD database (v4.1). This frequency is not significantly higher than estimated for a pathogenic variant in VARS2 causing Combined Oxidative Phosphorylation Defect Type 20, allowing no conclusion about variant significance. The variant, c.511C>T, has been observed in at least one compound heterozygous individual affected with Combined Oxidative Phosphorylation Defect Type 20 (Baertling_2017), who carried a pathogenic variant in trans. Authors of the study reported experimental evidence evaluating an impact on protein function, and demonstrated highly decreased VARS2 protein levels (residual protein level <30%) in patient derived fibroblasts (Baertling_2017). The following publication has been ascertained in the context of this evaluation (PMID: 27502409). ClinVar contains an entry for this variant (Variation ID: 488636). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

not provided Uncertain:1
Jan 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

VARS2: PM2, PM3 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.65
BayesDel_addAF
Benign
-0.15
T
BayesDel_noAF
Uncertain
-0.070
CADD
Pathogenic
29
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.36
T;.;D;.
Eigen
Uncertain
0.66
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Benign
0.38
N
LIST_S2
Pathogenic
1.0
D;D;D;D
M_CAP
Benign
0.036
D
MetaRNN
Uncertain
0.70
D;D;D;D
MetaSVM
Benign
-0.55
T
MutationAssessor
Pathogenic
4.4
H;.;.;.
PhyloP100
0.86
PrimateAI
Pathogenic
0.80
T
PROVEAN
Pathogenic
-7.2
D;.;D;D
REVEL
Uncertain
0.31
Sift
Pathogenic
0.0
D;.;D;D
Sift4G
Pathogenic
0.0
D;D;D;D
Polyphen
1.0
D;.;.;.
Vest4
0.98
MVP
0.56
MPC
1.3
ClinPred
1.0
D
GERP RS
4.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.86
gMVP
0.96
Mutation Taster
=8/92
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs139515727; hg19: chr6-30883762; API