16-66548963-A-C

Variant names:

• chr16-66548963-A-C
• rs80083556
• NM_004614.5:c.156+15T>G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6_Moderate

The NM_004614.5(TK2):​c.156+15T>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,611,310 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: TK2 NM_004614.5 intron
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.756
• Publications: 1 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: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
• autosomal recessive progressive external ophthalmoplegia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BP6: Variant 16-66548963-A-C is Benign according to our data. Variant chr16-66548963-A-C is described in ClinVar as Likely_benign. ClinVar VariationId is 2124724.Status of the report is criteria_provided_single_submitter, 1 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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TK2	NM_004614.5	MANE Select	c.156+15T>G		intron	N/A	NP_004605.4
	TK2	NM_001172645.2		c.156+15T>G		intron	N/A	NP_001166116.1
	TK2	NM_001172644.2		c.156+15T>G		intron	N/A	NP_001166115.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TK2	ENST00000544898.6	TSL:1 MANE Select	c.156+15T>G		intron	N/A	ENSP00000440898.2
	TK2	ENST00000451102.7	TSL:1	c.63+15T>G		intron	N/A	ENSP00000414334.4
	TK2	ENST00000527284.6	TSL:1	c.99+15T>G		intron	N/A	ENSP00000435312.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152116 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000796 AC: 2 AN: 251302 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

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: 0.000163

GnomAD4 exome AF: 0.00000343 AC: 5 AN: 1459194 Hom.: 0 Cov.: 29 AF XY: 0.00000689 AC XY: 5 AN XY: 726164

African (AFR) AF: 0.00 AC: 0 AN: 33384

American (AMR) AF: 0.00 AC: 0 AN: 44708

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26108

East Asian (EAS) AF: 0.00 AC: 0 AN: 39666

South Asian (SAS) AF: 0.00 AC: 0 AN: 86192

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53400

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5758

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1109696

Other (OTH) AF: 0.0000166 AC: 1 AN: 60282

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152116 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74318

African (AFR) AF: 0.00 AC: 0 AN: 41398

American (AMR) AF: 0.00 AC: 0 AN: 15270

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10622

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68014

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.0000203 Hom.: 71

ClinVar

ClinVar submissions as Germline

Significance: Likely benign

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	-	1	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	12
DANN	Benign	0.88
PhyloP100		0.76
PromoterAI		-0.0098	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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

Other links and lift over

dbSNP: rs80083556; hg19: chr16-66582866;