NM_001276345.2:c.691A>G

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_001276345.2(TNNT2):c.691A>G(p.Ile231Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000031 in 1,614,102 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. I231T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TNNT2
NM_001276345.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:12

Conservation

PhyloP100: 6.13

Publications

3 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

TNNT2 links:

ENSG00000286600 (HGNC:):

ENSG00000286600 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.756

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNT2	NM_001276345.2 link	c.691A>G	p.Ile231Val	missense_variant	Exon 14 of 17	ENST00000656932.1	NP_001263274.1	P45379-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TNNT2	ENST00000656932.1 link	c.691A>G	p.Ile231Val	missense_variant	Exon 14 of 17		NM_001276345.2	ENSP00000499593.1		P45379-1

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727246

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1112008

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74374

show subpopulations

African (AFR)

AF:

0.0000965

AC:

AN:

41444

American (AMR)

AF:

0.00

AC:

AN:

15290

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.438

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:12

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cardiomyopathy

Uncertain:2

Feb 22, 2024

All of Us Research Program, National Institutes of Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces isoleucine with valine at codon 221 of the TNNT2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TNNT2-related disorders in the literature. This variant has been identified in 2/31394 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. -

Mar 06, 2024

Color Diagnostics, LLC DBA Color Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Dilated cardiomyopathy 1D

Uncertain:1

Apr 11, 2023

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dilated Cardiomyopathy, Dominant

Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:1

Jun 18, 2024

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiomyopathy, familial restrictive, 3

Uncertain:1

Apr 11, 2023

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Left ventricular noncompaction cardiomyopathy

Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hypertrophic cardiomyopathy

Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Familial restrictive cardiomyopathy

Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Hypertrophic cardiomyopathy 2

Uncertain:1

Apr 11, 2023

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Jun 23, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.I221V variant (also known as c.661A>G), located in coding exon 12 of the TNNT2 gene, results from an A to G substitution at nucleotide position 661. The isoleucine at codon 221 is replaced by valine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. 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

Nov 10, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 221 of the TNNT2 protein (p.Ile221Val). This variant is present in population databases (no rsID available, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with TNNT2-related conditions. ClinVar contains an entry for this variant (Variation ID: 294895). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt TNNT2 protein function with a negative predictive value of 80%. 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

Benign

0.089

CardioboostCm

Benign

0.024

BayesDel_addAF

Uncertain

0.085

BayesDel_noAF

Benign

-0.12

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.52

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

Eigen

Benign

0.055

Eigen_PC

Benign

0.17

FATHMM_MKL

Benign

0.68

LIST_S2

Uncertain

0.94

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

M_CAP

Uncertain

0.17

MetaRNN

Pathogenic

0.76

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

MetaSVM

Uncertain

-0.20

MutationAssessor

Benign

1.9

.;.;.;.;L;.;.;.;.;.;.

PhyloP100

6.1

PrimateAI

Uncertain

0.53

PROVEAN

Benign

-0.61

N;N;.;.;.;.;.;.;N;N;N

REVEL

Uncertain

0.46

Sift

Benign

0.11

T;T;.;.;.;.;.;.;T;T;T

Sift4G

Benign

0.19

T;T;T;T;T;T;T;T;T;T;.

Polyphen

0.19

.;.;.;.;B;.;.;.;.;.;.

Vest4

0.49

MutPred

0.76

.;.;.;.;Gain of loop (P = 0.1081);.;.;.;.;.;.;

MVP

0.85

MPC

0.80

ClinPred

0.94

GERP RS

4.4

Varity_R

0.56

gMVP

0.61

Mutation Taster

=61/39

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over