rs17113613

Variant summary

Our verdict is Benign. The variant received -17 ACMG points: 3P and 20B. PM1PP2BP4_StrongBP6_Very_StrongBA1

The NM_021830.5(TWNK):​c.1102G>A​(p.Val368Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0213 in 1,614,092 control chromosomes in the GnomAD database, including 866 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

Frequency

Genomes: 𝑓 0.046 ( 346 hom., cov: 33)
Exomes 𝑓: 0.019 ( 520 hom. )

Consequence

TWNK
NM_021830.5 missense

Scores

2
15

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:13

Conservation

PhyloP100: 2.57

Publications

22 publications found
Variant links:
Genes affected
TWNK (HGNC:1160): (twinkle mtDNA helicase) This gene encodes a hexameric DNA helicase which unwinds short stretches of double-stranded DNA in the 5' to 3' direction and, along with mitochondrial single-stranded DNA binding protein and mtDNA polymerase gamma, is thought to play a key role in mtDNA replication. The protein localizes to the mitochondrial matrix and mitochondrial nucleoids. Mutations in this gene cause infantile onset spinocerebellar ataxia (IOSCA) and progressive external ophthalmoplegia (PEO) and are also associated with several mitochondrial depletion syndromes. Alternative splicing results in multiple transcript variants encoding distinct isoforms.[provided by RefSeq, Aug 2009]
TWNK Gene-Disease associations (from GenCC):
  • progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • mitochondrial DNA depletion syndrome 7 (hepatocerebral type)
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
  • autosomal dominant progressive external ophthalmoplegia
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • mitochondrial DNA depletion syndrome, hepatocerebrorenal form
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Perrault syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -17 ACMG points.

PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_021830.5
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 36 curated pathogenic missense variants (we use a threshold of 10). The gene has 6 curated benign missense variants. Gene score misZ: 1.6071 (below the threshold of 3.09). Trascript score misZ: 2.58 (below the threshold of 3.09). GenCC associations: The gene is linked to progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3, mitochondrial DNA depletion syndrome 7 (hepatocerebral type), Perrault syndrome, autosomal dominant progressive external ophthalmoplegia, mitochondrial DNA depletion syndrome, hepatocerebrorenal form.
BP4
Computational evidence support a benign effect (MetaRNN=0.00212875).
BP6
Variant 10-100989312-G-A is Benign according to our data. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-100989312-G-A is described in CliVar as Benign. Clinvar id is 136588.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BA1
GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.12 is higher than 0.05.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TWNKNM_021830.5 linkc.1102G>A p.Val368Ile missense_variant Exon 1 of 5 ENST00000311916.8 NP_068602.2 Q96RR1-1E5KSY5Q9H6V3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TWNKENST00000311916.8 linkc.1102G>A p.Val368Ile missense_variant Exon 1 of 5 1 NM_021830.5 ENSP00000309595.2 Q96RR1-1

Frequencies

GnomAD3 genomes
AF:
0.0462
AC:
7027
AN:
152126
Hom.:
341
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.123
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0323
Gnomad ASJ
AF:
0.00807
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00228
Gnomad FIN
AF:
0.0299
Gnomad MID
AF:
0.0222
Gnomad NFE
AF:
0.0143
Gnomad OTH
AF:
0.0474
GnomAD2 exomes
AF:
0.0220
AC:
5521
AN:
251324
AF XY:
0.0190
show subpopulations
Gnomad AFR exome
AF:
0.127
Gnomad AMR exome
AF:
0.0222
Gnomad ASJ exome
AF:
0.00387
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0307
Gnomad NFE exome
AF:
0.0153
Gnomad OTH exome
AF:
0.0231
GnomAD4 exome
AF:
0.0187
AC:
27363
AN:
1461848
Hom.:
520
Cov.:
32
AF XY:
0.0177
AC XY:
12875
AN XY:
727222
show subpopulations
African (AFR)
AF:
0.126
AC:
4234
AN:
33480
American (AMR)
AF:
0.0234
AC:
1047
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00440
AC:
115
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00392
AC:
338
AN:
86258
European-Finnish (FIN)
AF:
0.0301
AC:
1605
AN:
53376
Middle Eastern (MID)
AF:
0.0212
AC:
122
AN:
5768
European-Non Finnish (NFE)
AF:
0.0166
AC:
18466
AN:
1112012
Other (OTH)
AF:
0.0238
AC:
1436
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
1860
3720
5579
7439
9299
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
764
1528
2292
3056
3820
<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:
0.0463
AC:
7047
AN:
152244
Hom.:
346
Cov.:
33
AF XY:
0.0458
AC XY:
3411
AN XY:
74466
show subpopulations
African (AFR)
AF:
0.123
AC:
5118
AN:
41522
American (AMR)
AF:
0.0323
AC:
494
AN:
15308
Ashkenazi Jewish (ASJ)
AF:
0.00807
AC:
28
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.00207
AC:
10
AN:
4824
European-Finnish (FIN)
AF:
0.0299
AC:
317
AN:
10612
Middle Eastern (MID)
AF:
0.0238
AC:
7
AN:
294
European-Non Finnish (NFE)
AF:
0.0143
AC:
974
AN:
68018
Other (OTH)
AF:
0.0469
AC:
99
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.499
Heterozygous variant carriers
0
318
636
954
1272
1590
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
78
156
234
312
390
<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:
0.0221
Hom.:
338
Bravo
AF:
0.0505
TwinsUK
AF:
0.0129
AC:
48
ALSPAC
AF:
0.0122
AC:
47
ESP6500AA
AF:
0.124
AC:
546
ESP6500EA
AF:
0.0176
AC:
151
ExAC
AF:
0.0227
AC:
2762
Asia WGS
AF:
0.00924
AC:
33
AN:
3478
EpiCase
AF:
0.0146
EpiControl
AF:
0.0159

ClinVar

Significance: Benign
Submissions summary: Benign:13
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:5
Feb 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mar 09, 2016
Mayo Clinic Laboratories, Mayo Clinic
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Nov 06, 2023
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 30, 2018
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Breakthrough Genomics, Breakthrough Genomics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

not specified Benign:3
Jan 03, 2012
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Dec 05, 2014
Eurofins Ntd Llc (ga)
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive cerebellar ataxia Benign:1
Mar 06, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis Benign:1
Mar 06, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Hereditary spastic paraplegia Benign:1
Dec 21, 2021
Genome Diagnostics Laboratory, The Hospital for Sick Children
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal dominant 3 Benign:1
Mar 06, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Infantile onset spinocerebellar ataxia Benign:1
Mar 06, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Benign
-0.44
T
BayesDel_noAF
Benign
-0.29
CADD
Benign
22
DANN
Benign
0.92
DEOGEN2
Benign
0.084
T;.
Eigen
Benign
0.028
Eigen_PC
Benign
0.21
FATHMM_MKL
Uncertain
0.86
D
LIST_S2
Benign
0.85
D;T
MetaRNN
Benign
0.0021
T;T
MetaSVM
Benign
-0.75
T
MutationAssessor
Benign
0.92
L;L
PhyloP100
2.6
PROVEAN
Benign
-0.26
N;N
REVEL
Uncertain
0.35
Sift
Benign
0.58
T;T
Sift4G
Benign
0.73
T;T
Polyphen
0.53
P;B
Vest4
0.051
MPC
0.44
ClinPred
0.010
T
GERP RS
5.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.046
gMVP
0.46
Mutation Taster
=99/1
polymorphism (auto)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
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: rs17113613; hg19: chr10-102749069; COSMIC: COSV52966478; COSMIC: COSV52966478; API