dbSNP rs374319146: TBCK:c.1897+1G>T (chr4-106194717-C-A) – ACMG Classification: Pathogenic (10 pts)

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1PM2

The NM_001163435.3(TBCK):c.1897+1G>T variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000348 in 1,438,846 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000035 ( 0 hom. )

Consequence

TBCK
NM_001163435.3 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 7.47

Variant links:

Genes affected

TBCK (HGNC:28261): (TBC1 domain containing kinase) This gene encodes a protein that contains a protein kinase domain, a Rhodanase-like domain and the Tre-2/Bub2/Cdc16 (TBC) domain. The encoded protein is thought to play a role in actin organization, cell growth and cell proliferation by regulating the mammalian target of the rapamycin (mTOR) signaling pathway. This protein may also be involved in the transcriptional regulation of the components of the mTOR complex. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2014]

TBCK links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBCK	NM_001163435.3 link	c.1897+1G>T		splice_donor_variant, intron_variant	Intron 21 of 25	ENST00000394708.7	NP_001156907.2	Q8TEA7-1A0A024RDH3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TBCK	ENST00000394708.7 link	c.1897+1G>T		splice_donor_variant, intron_variant	Intron 21 of 25	1	NM_001163435.3	ENSP00000378198.2		Q8TEA7-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000435

AC:

AN:

230132

Hom.:

AF XY:

0.00000799

AC XY:

AN XY:

125230

show subpopulations

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000937

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000348

AC:

AN:

1438846

Hom.:

Cov.:

AF XY:

0.00000140

AC XY:

AN XY:

715798

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000121

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000272

Gnomad4 OTH exome

AF:

0.0000168

GnomAD4 genome

Cov.:

Alfa

AF:

0.00000961

Hom.:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Hypotonia, infantile, with psychomotor retardation and characteristic facies 3

Pathogenic:1

Jan 13, 2025

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

The c.1897+1G>T variant in TBCK has not been previously reported in the literature in individuals with TBCK-related intellectual disability syndrome, but has been identified in 0.001% (1/87198) of South Asian chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs374319146). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant is located in the 3' splice region. Computational tools predict a splicing impact, though this information is not predictive enough to determine pathogenicity. Loss of function of the TBCK gene is an established disease mechanism in autosomal recessive TBCK-related intellectual disability syndrome. One additional pathogenic variant, predicted to induce the same splicing effect as this variant, has been reported in ClinVar as being associated with TBCK-related intellectual disability syndrome, supporting that the variant may be pathogenic (Variation ID: 183338). In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive TBCK-related intellectual disability syndrome. ACMG/AMP Criteria applied: PVS1, PM2_supporting, PS1_supporting (Richards 2015). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.44

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.72

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.72

Position offset: 1

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

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