rs1555669421

Variant names:

• chr17-62612404-C-T
• rs1555669421
• NM_006852.6:c.2092C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_006852.6(TLK2):​c.2092C>T​(p.Arg698*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TLK2 NM_006852.6 stop_gained
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:1
• Conservation: PhyloP100: 3.99
• Publications: 1 publications found

Genes affected

TLK2 (HGNC:11842): (tousled like kinase 2) This gene encodes a nuclear serine/threonine kinase that was first identified in Arabidopsis. The encoded protein is thought to function in the regulation of chromatin assembly in the S phase of the cell cycle by regulating the levels of a histone H3/H4 chaperone. This protein is associated with double-strand break repair of DNA damage caused by radiation. Pseudogenes of this gene are present on chromosomes 10 and 17. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Sep 2013]

TLK2 Gene-Disease associations (from GenCC):

• intellectual disability, autosomal dominant 57

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: G2P, Illumina, Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-62612404-C-T is Pathogenic according to our data. Variant chr17-62612404-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 489247.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TLK2	NM_006852.6	c.2092C>T	p.Arg698*	stop_gained	Exon 22 of 22	ENST00000346027.10	NP_006843.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TLK2	ENST00000346027.10	c.2092C>T	p.Arg698*	stop_gained	Exon 22 of 22	1	NM_006852.6	ENSP00000275780.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:2

Mar 25, 2020

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant in the C-terminus predicted to result in protein truncation, as the last 53 amino acids are lost, and other loss-of-function variants have been reported downstream at GeneDx and in the Human Gene Mutation Database (Stenson et al., 2014); Not observed in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 27479843, 29861108) -

Oct 23, 2020

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Intellectual disability, autosomal dominant 57 Pathogenic:1 Uncertain:1

Apr 29, 2022

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Oct 15, 2018

SIB Swiss Institute of Bioinformatics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: curation

This variant is interpreted as Uncertain Significance - Insufficient Evidence, for Mental retardation, autosomal dominant 57. The following ACMG Tag(s) were applied: PM2 => Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium. PM6 => Assumed de novo, but without confirmation of paternity and maternity (https://www.ncbi.nlm.nih.gov/pubmed/27479843) (https://www.ncbi.nlm.nih.gov/pubmed/29861108). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.61	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	39
DANN	Uncertain	1.0
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Uncertain	0.96	D
PhyloP100		4.0
Vest4		0.46
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.070		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: rs1555669421; hg19: chr17-60689765;