rs886045828

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP3

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

1
8
11

Clinical Significance

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

Conservation

PhyloP100: 6.13
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PM1
In a chain Troponin T, cardiac muscle (size 296) in uniprot entity TNNT2_HUMAN there are 176 pathogenic changes around while only 18 benign (91%) in NM_001276345.2
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
TNNT2NM_001276345.2 linkc.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
TNNT2ENST00000656932.1 linkc.691A>G p.Ile231Val missense_variant Exon 14 of 17 NM_001276345.2 ENSP00000499593.1 P45379-1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152214
Hom.:
0
Cov.:
33
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:
1
AN:
1461888
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727246
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:
8.99e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152214
Hom.:
0
Cov.:
33
AF XY:
0.0000403
AC XY:
3
AN XY:
74374
show subpopulations
Gnomad4 AFR
AF:
0.0000965
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:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000282
Hom.:
0
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. -

Jan 23, 2023
Color Diagnostics, LLC DBA Color 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. -

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

- -

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

- -

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

- -

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

- -

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. -

Hypertrophic cardiomyopathy 2 Uncertain:1
Apr 11, 2023
Genome-Nilou Lab
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

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
D
BayesDel_noAF
Benign
-0.12
CADD
Uncertain
24
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.52
.;.;.;.;D;.;.;.;.;.;T
Eigen
Benign
0.055
Eigen_PC
Benign
0.17
FATHMM_MKL
Benign
0.68
D
LIST_S2
Uncertain
0.94
.;D;D;D;D;D;D;.;.;D;.
M_CAP
Uncertain
0.17
D
MetaRNN
Pathogenic
0.76
D;D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
-0.20
T
MutationAssessor
Benign
1.9
.;.;.;.;L;.;.;.;.;.;.
PrimateAI
Uncertain
0.53
T
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
D
GERP RS
4.4
Varity_R
0.56
gMVP
0.61

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.

Other links and lift over

dbSNP: rs886045828; hg19: chr1-201331069; API