chr16-66509549-G-A

Variant names:

• chr16-66509549-G-A
• rs74372298
• NM_004614.5:c.*2419C>T

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BA1

The NM_004614.5(TK2):​c.*2419C>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 0.024 in 152,324 control chromosomes in the GnomAD database, including 150 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

• Frequency:
  • Genomes: 𝑓 0.024 (150 hom., cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TK2 NM_004614.5 3_prime_UTR
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 0.0870
• Publications: 2 publications found

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: Labcorp Genetics (formerly Invitae), G2P, Orphanet
• autosomal recessive progressive external ophthalmoplegia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000260851 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.9).
• BP6: Variant 16-66509549-G-A is Benign according to our data. Variant chr16-66509549-G-A is described in ClinVar as Benign. ClinVar VariationId is 320125.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.0799 is higher than 0.05.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TK2	NM_004614.5	MANE Select	c.*2419C>T		3_prime_UTR	Exon 10 of 10	NP_004605.4
	TK2	NM_001172645.2		c.*2419C>T		3_prime_UTR	Exon 9 of 9	NP_001166116.1	O00142-4
	TK2	NM_001172644.2		c.*2419C>T		3_prime_UTR	Exon 9 of 9	NP_001166115.1	O00142-3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TK2	ENST00000544898.6	TSL:1 MANE Select	c.*2419C>T		3_prime_UTR	Exon 10 of 10	ENSP00000440898.2	O00142-1
	TK2	ENST00000451102.7	TSL:1	c.*2419C>T		3_prime_UTR	Exon 10 of 10	ENSP00000414334.4	O00142-2
	TK2	ENST00000299697.12	TSL:1	c.*2419C>T		3_prime_UTR	Exon 9 of 9	ENSP00000299697.9	A0A7P0MLU2

Frequencies

GnomAD3 genomes AF: 0.0240 AC: 3655 AN: 152206 Hom.: 150 Cov.: 33

Gnomad AFR AF: 0.0824

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0118

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.0000941

Gnomad MID AF: 0.00949

Gnomad NFE AF: 0.000397

Gnomad OTH AF: 0.0144

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 6 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 6

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AC: 0 AN: 0

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 2

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 4

Other (OTH) AC: 0 AN: 0

GnomAD4 genome AF: 0.0240 AC: 3659 AN: 152324 Hom.: 150 Cov.: 33 AF XY: 0.0235 AC XY: 1748 AN XY: 74498

African (AFR) AF: 0.0822 AC: 3417 AN: 41558

American (AMR) AF: 0.0118 AC: 180 AN: 15304

Ashkenazi Jewish (ASJ) AF: 0.000288 AC: 1 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.0000941 AC: 1 AN: 10622

Middle Eastern (MID) AF: 0.0102 AC: 3 AN: 294

European-Non Finnish (NFE) AF: 0.000397 AC: 27 AN: 68028

Other (OTH) AF: 0.0142 AC: 30 AN: 2112

Alfa AF: 0.0104 Hom.: 16

Bravo AF: 0.0270

Asia WGS AF: 0.00346 AC: 12 AN: 3478

ClinVar

ClinVar submissions as Germline

Significance: Benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Mitochondrial DNA depletion syndrome, myopathic form (1)
-	-	1	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.90
CADD	Benign	1.7
DANN	Benign	0.74
PhyloP100		0.087
Mutation Taster		=95/5	polymorphism

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

Other links and lift over

dbSNP: rs74372298; hg19: chr16-66543452;