dbSNP rs137886900: TK2:p.Arg183Trp (chr16-66517207-G-A) – ACMG Classification: Pathogenic (15 pts)

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PM1PM2PM5PP3PP5_Very_Strong

The NM_004614.5(TK2):c.547C>T(p.Arg183Trp) variant causes a missense change. The variant allele was found at a frequency of 0.0000781 in 1,613,922 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R183Q) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000092 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000077 ( 0 hom. )

Consequence

TK2
NM_004614.5 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7O:1

Conservation

PhyloP100: 5.18

Publications

19 publications found

Variant links:

Genes affected

TK2 (HGNC:11831): (thymidine kinase 2) This gene encodes a deoxyribonucleoside kinase that specifically phosphorylates thymidine, deoxycytidine, and deoxyuridine. The encoded enzyme localizes to the mitochondria and is required for mitochondrial DNA synthesis. Mutations in this gene are associated with a myopathic form of mitochondrial DNA depletion syndrome. Alternate splicing results in multiple transcript variants encoding distinct isoforms, some of which lack transit peptide, so are not localized to mitochondria. [provided by RefSeq, Dec 2012]

TK2 Gene-Disease associations (from GenCC):

mitochondrial disease
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
mitochondrial DNA depletion syndrome, myopathic form
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: PanelApp Australia, Orphanet, Labcorp Genetics (formerly Invitae), G2P
autosomal recessive progressive external ophthalmoplegia
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

TK2 links:

ENSG00000260851 (HGNC:):

ENSG00000260851 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 15 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_004614.5

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr16-66517207-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 38991.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.827

PP5

Variant 16-66517207-G-A is Pathogenic according to our data. Variant chr16-66517207-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 38992.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004614.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
TK2	NM_004614.5	MANE Select	c.547C>T	p.Arg183Trp	missense	Exon 8 of 10	NP_004605.4
TK2	NM_001172645.2		c.493C>T	p.Arg165Trp	missense	Exon 7 of 9	NP_001166116.1	O00142-4
TK2	NM_001172644.2		c.472C>T	p.Arg158Trp	missense	Exon 7 of 9	NP_001166115.1	O00142-3

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
TK2	ENST00000544898.6	TSL:1 MANE Select	c.547C>T	p.Arg183Trp	missense	Exon 8 of 10	ENSP00000440898.2	O00142-1
TK2	ENST00000451102.7	TSL:1	c.454C>T	p.Arg152Trp	missense	Exon 8 of 10	ENSP00000414334.4	O00142-2
TK2	ENST00000527284.6	TSL:1	c.490C>T	p.Arg164Trp	missense	Exon 8 of 9	ENSP00000435312.2	A0A7P0PE46

Frequencies

GnomAD3 genomes

AF:

0.0000920

AC:

AN:

152128

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.000661

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.000956

GnomAD2 exomes

AF:

0.000107

AC:

AN:

251488

AF XY:

0.0000956

show subpopulations

Gnomad AFR exome

AF:

0.000246

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.000693

Gnomad NFE exome

AF:

0.0000527

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000766

AC:

112

AN:

1461794

Hom.:

Cov.:

AF XY:

0.0000811

AC XY:

AN XY:

727206

show subpopulations

African (AFR)

AF:

0.000119

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.000842

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000504

AC:

AN:

1111920

Other (OTH)

AF:

0.0000993

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.467

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000920

AC:

AN:

152128

Hom.:

Cov.:

AF XY:

0.000135

AC XY:

AN XY:

74292

show subpopulations

African (AFR)

AF:

0.0000483

AC:

AN:

41434

American (AMR)

AF:

0.00

AC:

AN:

15266

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.000661

AC:

AN:

10584

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

68030

Other (OTH)

AF:

0.000956

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.507

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.0000959

Hom.:

Bravo

AF:

0.0000378

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ExAC

AF:

0.0000906

AC:

ClinVar

ClinVar submissions

Significance:Pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Mitochondrial DNA depletion syndrome, myopathic form (3)

not provided (2)

Mitochondrial disease (1)

Mitochondrial DNA depletion syndrome (1)

Progressive external ophthalmoplegia with mitochondrial DNA deletions, autosomal recessive 3 (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.29

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.47

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.97

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.73

FATHMM_MKL

Uncertain

0.78

LIST_S2

Pathogenic

0.99

M_CAP

Pathogenic

0.45

MetaRNN

Pathogenic

0.83

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.0

PhyloP100

5.2

PrimateAI

Benign

0.32

PROVEAN

Pathogenic

-5.9

REVEL

Pathogenic

0.92

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.82

MutPred

0.73

Gain of catalytic residue at P228 (P = 0.0456)

MVP

1.0

MPC

1.1

ClinPred

0.88

GERP RS

5.6

Varity_R

0.84

gMVP

0.62

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

Splicevardb

1.0

SpliceAI score (max)

0.060

Details are displayed if max score is > 0.2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over