1-201359224-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM1BP4_ModerateBS2

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 same amino acid change has been previously reported as Uncertain significancein 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

Clinical Significance

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

Conservation

PhyloP100: 2.30

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 Likely_benign. Variant got -4 ACMG points.

PM1

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

BP4

Computational evidence support a benign effect (MetaRNN=0.25154516).

BS2

High AC in GnomAdExome at 8 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNT2	NM_001276345.2 linkuse as main transcript	c.883G>A	p.Gly295Arg	missense_variant	17/17	ENST00000656932.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TNNT2	ENST00000656932.1 linkuse as main transcript	c.883G>A	p.Gly295Arg	missense_variant	17/17		NM_001276345.2	A2	P45379-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152146

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:

0.000192

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

GnomAD3 exomes

AF:

0.0000328

AC:

AN:

243624

Hom.:

AF XY:

0.0000304

AC XY:

AN XY:

131466

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000272

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000103

AC:

AN:

1458452

Hom.:

Cov.:

AF XY:

0.00000966

AC XY:

AN XY:

724964

show subpopulations

Gnomad4 AFR exome

AF:

0.0000598

Gnomad4 AMR exome

AF:

0.0000226

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000757

Gnomad4 SAS exome

AF:

0.0000118

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152264

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74454

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000189

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000494

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:9

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cardiomyopathy

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Apr 19, 2023	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. -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Nov 02, 2023	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

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Mar 17, 2022

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

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Primary familial hypertrophic cardiomyopathy

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Blueprint Genetics

Oct 07, 2014

- -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 22, 2021

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. -

Hypertrophic cardiomyopathy 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 11, 2024

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). 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 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

BayesDel_noAF

Benign

-0.16

Cadd

Pathogenic

Dann

Uncertain

1.0

Eigen

Uncertain

0.25

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Uncertain

0.94

M_CAP

Uncertain

0.19

MetaRNN

Benign

0.25

T;T;T;T;T;T;T;T;T;T

MetaSVM

Benign

-1.1

MutationTaster

Benign

1.0

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

PrimateAI

Pathogenic

0.83

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

GERP RS

4.0

Varity_R

0.19

gMVP

0.36

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

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