1-201364351-C-T

Position:

chr1-201364351-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PM1PP3_ModerateBS2

The NM_001276345.2(TNNT2):c.436G>A(p.Glu146Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,104 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E146D) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

TNNT2
NM_001276345.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:8

Conservation

PhyloP100: 7.67

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 Uncertain_significance. Variant got 0 ACMG points.

PM1

In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_001276345.2

PP3

MetaRNN computational evidence supports a deleterious effect, 0.91

BS2

High AC in GnomAdExome4 at 9 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNT2	NM_001276345.2 linkuse as main transcript	c.436G>A	p.Glu146Lys	missense_variant	11/17	ENST00000656932.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TNNT2	ENST00000656932.1 linkuse as main transcript	c.436G>A	p.Glu146Lys	missense_variant	11/17		NM_001276345.2	A2	P45379-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152230

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:

0.00000800

AC:

AN:

250114

Hom.:

AF XY:

0.00000739

AC XY:

AN XY:

135390

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:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000616

AC:

AN:

1460874

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

726794

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:

0.00000809

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152230

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74366

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:

0.0000189

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cardiomyopathy

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Feb 05, 2024	This missense variant replaces glutamic acid with lysine at codon 136 in the tropomyosin binding domain of the TNNT2 protein. Computational prediction suggests that this variant may have a deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). An experimental functional study has shown that this variant may affect the actin-myosin interactions in in vitro motility assay and affect the heart function in transgenic Drosophila model (PMID: 32690703; Madan et al., 2019). However, clinical relevance of these observations is not clear. This variant has been reported in individuals affected with dilated cardiomyopathy (PMID: 28416588, 32659924). This variant has also been reported in an individual affected with restrictive cardiomyopathy, as well as in an unaffected parent and sibling (PMID: 18467357). This variant has been identified in 3/281494 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Apr 27, 2023	This missense variant replaces glutamic acid with lysine at codon 136 in the tropomyosin binding domain of the TNNT2 protein. Computational prediction suggests that this variant may have a deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). An experimental functional study has shown that this variant may affect the actin-myosin interactions in in vitro motility assay and affect the heart function in transgenic Drosophila model (PMID: 32690703; Madan et al., 2019). However, clinical relevance of these observations is not clear. This variant has been reported in individuals affected with dilated cardiomyopathy (PMID: 28416588, 32659924). This variant has also been reported in an individual affected with restrictive cardiomyopathy, as well as in an unaffected parent and sibling (PMID: 18467357). This variant has been identified in 3/281494 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Dilated cardiomyopathy 1D

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Cardiomyopathy, familial restrictive, 3

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Primary dilated cardiomyopathy

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Blueprint Genetics

Sep 29, 2014

- -

Hypertrophic cardiomyopathy 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 19, 2024

The p.E136K variant (also known as c.406G>A), located in coding exon 9 of the TNNT2 gene, results from a G to A substitution at nucleotide position 406. The glutamic acid at codon 136 is replaced by lysine, an amino acid with similar properties. This variant (also referred to as p.E131K) has been detected individuals from dilated cardiomyopathy cohorts, and in a proband with restrictive cardiomyopathy as well as two clinically unaffected relatives (Kaski JP et al. Heart. 2008;94:1478-84; Dal Ferro M et al. Heart. 2017;103:1704-1710; Kolokotronis K et al. J Clin Med. 2020 Jul;9(7)). In studies of drosophila and rat cardiomyocytes expressing this variant, some disease features were recapitulated (Madan A et al. Proc Natl Acad Sci U S A . 2020 Aug;117(31):18822-18831). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Dilated cardiomyopathy 1D;C1861864:Hypertrophic cardiomyopathy 2;C2676271:Cardiomyopathy, familial restrictive, 3

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 04, 2023

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 136 of the TNNT2 protein (p.Glu136Lys). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individuals with clinical features of TNNT2-related conditions (PMID: 18467357, 28416588, 32659924). This variant is also known as c.391G>A (p.E131K). ClinVar contains an entry for this variant (Variation ID: 180552). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt TNNT2 protein function. Experimental studies have shown that this missense change affects TNNT2 function (PMID: 32690703). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.68

CardioboostCm

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.27

BayesDel_noAF

Pathogenic

0.17

CADD

Pathogenic

DANN

Pathogenic

1.0

Eigen

Uncertain

0.68

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Pathogenic

0.99

M_CAP

Pathogenic

0.89

MetaRNN

Pathogenic

0.91

D;D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Pathogenic

1.0

MutationTaster

Benign

1.0

D;D;D;D;D;D;D;D;D;D

PrimateAI

Uncertain

0.78

PROVEAN

Uncertain

-3.5

D;D;.;D;.;.;.;.;D;D;D;D

REVEL

Pathogenic

0.79

Sift

Uncertain

0.0090

D;D;.;D;.;.;.;.;D;D;D;D

Sift4G

Uncertain

0.020

D;T;T;T;D;D;D;D;T;D;.;T

Polyphen

1.0

.;.;.;.;D;.;.;.;.;.;D;.

Vest4

0.72

MVP

0.98

MPC

1.3

ClinPred

0.94

GERP RS

4.3

Varity_R

0.40

gMVP

0.96

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

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