1-201359224-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM1BP4_Moderate

The NM_001276345.2(TNNT2):​c.883G>A​(p.Gly295Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000993 in 1,610,716 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G295E) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000010 ( 0 hom. )

Consequence

TNNT2
NM_001276345.2 missense

Scores

3
7
10

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:9

Conservation

PhyloP100: 2.30

Publications

7 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: Uncertain_significance. The variant received 0 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_001276345.2
BP4
Computational evidence support a benign effect (MetaRNN=0.25154516).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TNNT2NM_001276345.2 linkc.883G>A p.Gly295Arg missense_variant Exon 17 of 17 ENST00000656932.1 NP_001263274.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TNNT2ENST00000656932.1 linkc.883G>A p.Gly295Arg missense_variant Exon 17 of 17 NM_001276345.2 ENSP00000499593.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152146
Hom.:
0
Cov.:
32
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:
0.000192
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
GnomAD2 exomes
AF:
0.0000328
AC:
8
AN:
243624
AF XY:
0.0000304
show subpopulations
Gnomad AFR exome
AF:
0.000128
Gnomad AMR exome
AF:
0.0000295
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000111
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000272
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000103
AC:
15
AN:
1458452
Hom.:
0
Cov.:
31
AF XY:
0.00000966
AC XY:
7
AN XY:
724964
show subpopulations
African (AFR)
AF:
0.0000598
AC:
2
AN:
33462
American (AMR)
AF:
0.0000226
AC:
1
AN:
44312
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26020
East Asian (EAS)
AF:
0.0000757
AC:
3
AN:
39630
South Asian (SAS)
AF:
0.0000118
AC:
1
AN:
84822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53204
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5682
European-Non Finnish (NFE)
AF:
0.00000630
AC:
7
AN:
1111044
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60276
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
1
2
3
4
5
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:
152264
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74454
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41540
American (AMR)
AF:
0.00
AC:
0
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68012
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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:
0.0000267
Hom.:
0
Bravo
AF:
0.0000189
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000494
AC:
6

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Cardiomyopathy Uncertain:2
May 16, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces glycine with arginine at codon 285 of the TNNT2 protein. Computational prediction tools indicate that this variant has a neutral impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in one individual affected with hypertrophic cardiomyopathy (PMID: 32492895). This variant has been identified in 9/274990 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. -

Sep 23, 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 glycine with arginine at codon 285 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 been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 32492895). This variant has been identified in 9/274990 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

- -

not provided Uncertain:1
Mar 17, 2022
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Identified in a patient with HCM in the published literature (Kim et al., 2020); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32492895) -

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

- -

Primary familial hypertrophic cardiomyopathy Uncertain:1
Oct 07, 2014
Blueprint Genetics
Significance:Uncertain significance
Review Status:no assertion criteria provided
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
Dec 22, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.G285R variant (also known as c.853G>A), located in coding exon 15 of the TNNT2 gene, results from a G to A substitution at nucleotide position 853. The glycine at codon 285 is replaced by arginine, an amino acid with dissimilar properties. This alteration has been reported in a hypertrophic cardiomyopathy (HCM) cohort; however, clinical details were limited (Kim HY et al. J Clin Med, 2020 Jun;9:[ePub ahead of print]). This amino acid position is highly conserved in available vertebrate species. 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
Sep 01, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 285 of the TNNT2 protein (p.Gly285Arg). This variant is present in population databases (rs147940106, gnomAD 0.009%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 31513939). ClinVar contains an entry for this variant (Variation ID: 180555). 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 expected to disrupt TNNT2 protein function with a positive predictive value of 95%. 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
0.97
CardioboostCm
Benign
0.077
BayesDel_addAF
Benign
-0.12
T
BayesDel_noAF
Benign
-0.16
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.74
.;.;.;.;D;.;.;.;.;.
Eigen
Uncertain
0.25
Eigen_PC
Uncertain
0.29
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Pathogenic
1.0
.;D;D;D;D;D;D;.;.;D
M_CAP
Uncertain
0.19
D
MetaRNN
Benign
0.25
T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
1.8
.;.;.;.;L;.;.;.;.;.
PhyloP100
2.3
PrimateAI
Pathogenic
0.83
D
PROVEAN
Uncertain
-3.1
D;D;D;.;.;.;.;.;D;D
REVEL
Benign
0.11
Sift
Benign
0.057
T;T;D;.;.;.;.;.;D;T
Sift4G
Benign
0.081
T;T;T;T;T;T;T;T;T;T
Polyphen
0.91
.;.;.;.;P;.;.;.;.;.
Vest4
0.20
MutPred
0.63
.;.;.;.;Loss of methylation at R296 (P = 0.03);.;.;.;.;.;
MVP
0.91
MPC
1.5
ClinPred
0.24
T
GERP RS
4.0
Varity_R
0.19
gMVP
0.36
Mutation Taster
=40/60
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs147940106; hg19: chr1-201328352; COSMIC: COSV52662848; COSMIC: COSV52662848; API