rs377474357

Positions:

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 10P and 4B. PVS1PP3_ModerateBS2

The NM_001276345.2(TNNT2):c.97G>T(p.Glu33Ter) variant causes a stop gained, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000204 in 1,614,064 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. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

TNNT2
NM_001276345.2 stop_gained, splice_region

Scores

Splicing: ADA: 0.9998

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 2.53

Variant links:

Genes affected

TNNT2 (HGNC:11949): (troponin T2, cardiac type) This gene encodes the cardiac isoform of troponin T. The encoded protein is the tropomyosin-binding subunit of the troponin complex, which is located on the thin filament of striated muscles and regulates muscle contraction in response to alterations in intracellular calcium ion concentration. Mutations in this gene have been associated with familial hypertrophic cardiomyopathy as well as with dilated cardiomyopathy. [provided by RefSeq, May 2022]

TNNT2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 187 pathogenic variants in the truncated region.

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

BS2

High AC in GnomAdExome4 at 32 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNT2	NM_001276345.2 linkuse as main transcript	c.97G>T	p.Glu33Ter	stop_gained, splice_region_variant	5/17	ENST00000656932.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TNNT2	ENST00000656932.1 linkuse as main transcript	c.97G>T	p.Glu33Ter	stop_gained, splice_region_variant	5/17		NM_001276345.2	A2	P45379-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152204

Hom.:

Cov.:

show subpopulations

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

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251418

Hom.:

AF XY:

0.00000736

AC XY:

AN XY:

135892

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:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000219

AC:

AN:

1461860

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

727228

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000270

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152204

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74348

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	May 09, 2018	The E33X variant of uncertain significance in the TNNT2 gene has not been published as pathogenic or been reported as benign to our knowledge. This variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). However, E33X was identified in 5 alleles from presumably unaffected individuals referred for genetic testing at GeneDx. The E33X variant is predicted to cause loss of normal protein function either by protein truncation or nonsense-mediated mRNA decay. However, only one nonsense variant in the TNNT2 gene has been reported in Human Gene Mutation Database in association with cardiomyopathy (Stenson et al., 2014), indicating loss of function is not a known mechanism for disease in the TNNT2 gene. Therefore, based on the currently available information, it is unclear whether this variant is pathogenic or benign. -
Uncertain significance, no assertion criteria provided	clinical testing	Department of Pathology and Laboratory Medicine, Sinai Health System	-	The TNNT2 p.Glu33* variant was not identified in the literature nor was it identified in LOVD 3.0. The variant was identified in dbSNP (ID: rs377474357) and ClinVar (classified as a VUS by GeneDx). The variant was identified in control databases in 1 of 251418 chromosomes at a frequency of 0.000003977 (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the European (non-Finnish) population in 1 of 113716 chromosomes (freq: 0.000009) but was not observed in the African, Latino, Ashkenazi Jewish, East Asian, European (Finnish), Other or South Asian populations. The c.97G>T variant leads to a premature stop codon at position 33 which is predicted to lead to a truncated or absent protein and loss of function. It is currently unclear whether loss of function variants of the TNNT2 gene are a mechanism of disease. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	AiLife Diagnostics, AiLife Diagnostics	Feb 25, 2022	- -

Dilated cardiomyopathy 1D

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Nov 04, 2023

- -

Cardiomyopathy, familial restrictive, 3

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Nov 04, 2023

- -

Hypertrophic cardiomyopathy 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Nov 04, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Benign

-0.36

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Benign

-0.17

Eigen_PC

Benign

-0.17

FATHMM_MKL

Uncertain

0.83

MutationTaster

Benign

1.0

A;A;A;D;D;D;D;D;D;D

Vest4

0.58

GERP RS

3.4

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.90

SpliceAI score (max)

0.67

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.67

Position offset: 0

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

Other links and lift over