16-66509428-C-A

Variant summary

Our verdict is Benign. Variant got -8 ACMG points: 2P and 10B. PM2BP4_StrongBP6_ModerateBS1

The NM_004614.5(TK2):​c.*2540G>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00358 in 152,240 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

Frequency

Genomes: 𝑓 0.0036 ( 1 hom., cov: 33)
Exomes 𝑓: 0.0 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

TK2
NM_004614.5 3_prime_UTR

Scores

2

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: -1.50
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -8 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.92).
BP6
Variant 16-66509428-C-A is Benign according to our data. Variant chr16-66509428-C-A is described in ClinVar as [Likely_benign]. Clinvar id is 887548.Status of the report is criteria_provided_single_submitter, 1 stars.
BS1
Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.00358 (545/152240) while in subpopulation SAS AF= 0.00704 (34/4828). AF 95% confidence interval is 0.00518. There are 1 homozygotes in gnomad4. There are 257 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
TK2NM_004614.5 linkuse as main transcriptc.*2540G>T 3_prime_UTR_variant 10/10 ENST00000544898.6 NP_004605.4

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
TK2ENST00000544898.6 linkuse as main transcriptc.*2540G>T 3_prime_UTR_variant 10/101 NM_004614.5 ENSP00000440898 P1O00142-1
ENST00000568560.1 linkuse as main transcript upstream_gene_variant 5

Frequencies

GnomAD3 genomes
AF:
0.00358
AC:
545
AN:
152122
Hom.:
1
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00114
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00144
Gnomad ASJ
AF:
0.0132
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00704
Gnomad FIN
AF:
0.00113
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00553
Gnomad OTH
AF:
0.00383
GnomAD4 exome
Data not reliable, filtered out with message: AC0
AF:
0.00
AC:
0
AN:
4
Hom.:
0
Cov.:
0
AF XY:
0.00
AC XY:
0
AN XY:
4
Gnomad4 SAS exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00
GnomAD4 genome
AF:
0.00358
AC:
545
AN:
152240
Hom.:
1
Cov.:
33
AF XY:
0.00345
AC XY:
257
AN XY:
74428
show subpopulations
Gnomad4 AFR
AF:
0.00113
Gnomad4 AMR
AF:
0.00144
Gnomad4 ASJ
AF:
0.0132
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00704
Gnomad4 FIN
AF:
0.00113
Gnomad4 NFE
AF:
0.00553
Gnomad4 OTH
AF:
0.00379
Alfa
AF:
0.00122
Hom.:
0
Bravo
AF:
0.00359
Asia WGS
AF:
0.00346
AC:
12
AN:
3478

ClinVar

Significance: Likely benign
Submissions summary: Benign:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Mitochondrial DNA depletion syndrome, myopathic form Benign:1
Likely benign, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaJan 13, 2018This 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 likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.92
CADD
Benign
0.11
DANN
Benign
0.29

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

LitVar

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

Other links and lift over

dbSNP: rs574199934; hg19: chr16-66543331; COSMIC: COSV55284140; COSMIC: COSV55284140; API