rs377474357

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1PP3_Moderate

The NM_001276345.2(TNNT2):​c.97G>T​(p.Glu33*) 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

1
2
4
Splicing: ADA: 0.9998
2

Clinical Significance

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

Conservation

PhyloP100: 2.53

Publications

2 publications found
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 Gene-Disease associations (from GenCC):
  • dilated cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • dilated cardiomyopathy 1D
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • hypertrophic cardiomyopathy 2
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
  • hypertrophic cardiomyopathy 3
    Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
  • cardiomyopathy, familial restrictive, 3
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial isolated restrictive cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • left ventricular noncompaction
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • cardiomyopathy
    Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
  • arrhythmogenic right ventricular cardiomyopathy
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 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 96 pathogenic variants in the truncated region.
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TNNT2NM_001276345.2 linkc.97G>T p.Glu33* stop_gained, splice_region_variant Exon 5 of 17 ENST00000656932.1 NP_001263274.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TNNT2ENST00000656932.1 linkc.97G>T p.Glu33* stop_gained, splice_region_variant Exon 5 of 17 NM_001276345.2 ENSP00000499593.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152204
Hom.:
0
Cov.:
33
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
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251418
AF XY:
0.00000736
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000219
AC:
32
AN:
1461860
Hom.:
0
Cov.:
35
AF XY:
0.0000220
AC XY:
16
AN XY:
727228
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000270
AC:
30
AN:
1112000
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.444
Heterozygous variant carriers
0
2
4
7
9
11
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152204
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74348
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41434
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68038
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000282
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:3
May 09, 2018
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. -

-
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

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. -

Feb 25, 2022
AiLife Diagnostics, AiLife Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dilated cardiomyopathy 1D Uncertain:1
Nov 04, 2023
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy, familial restrictive, 3 Uncertain:1
Nov 04, 2023
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hypertrophic cardiomyopathy 2 Uncertain:1
Nov 04, 2023
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Benign
-0.36
CADD
Pathogenic
59
DANN
Uncertain
1.0
Eigen
Benign
-0.17
Eigen_PC
Benign
-0.17
FATHMM_MKL
Uncertain
0.83
D
PhyloP100
2.5
Vest4
0.58
GERP RS
3.4
Mutation Taster
=11/189
disease causing (fs/PTC)

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

Other links and lift over

dbSNP: rs377474357; hg19: chr1-201338944; API