rs727504331

Positions:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong

The NM_001276345.2(TNNT2):c.360T>G(p.Phe120Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,888 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F120V) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TNNT2
NM_001276345.2 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:11

Conservation

PhyloP100: 0.363

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 Pathogenic. Variant got 16 ACMG points.

PM1

In a region_of_interest Disordered (size 99) in uniprot entity TNNT2_HUMAN there are 38 pathogenic changes around while only 2 benign (95%) in NM_001276345.2

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chrnull-null-null-null is described in UniProt as null.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.885

PP5

Variant 1-201365242-A-C is Pathogenic according to our data. Variant chr1-201365242-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 177807.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-201365242-A-C is described in Lovd as [Pathogenic]. Variant chr1-201365242-A-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TNNT2	NM_001276345.2 linkuse as main transcript	c.360T>G	p.Phe120Leu	missense_variant	10/17	ENST00000656932.1	NP_001263274.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TNNT2	ENST00000656932.1 linkuse as main transcript	c.360T>G	p.Phe120Leu	missense_variant	10/17		NM_001276345.2	ENSP00000499593	A2	P45379-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000795

AC:

AN:

251494

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135922

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:

0.0000462

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00

AC XY:

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:

0.0000187

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:11

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Oct 09, 2023	Segregates with HCM in at least three affected relatives from one family (PMID: 14636924); A different nucleotide change resulting in the same amino acid substitution (c.328 T>C, p.(F110L)) has also been reported, and some publications only describe the variant at the protein level and do not specify the nucleotide substitution.; Not observed at significant frequency in large population cohorts (gnomAD); 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: 7898523, 20031601, 16858239, 18533079, 27532257, 22144547, 33673806, 36252119, 36578016, 14636924, 25524337) -
Likely pathogenic, criteria provided, single submitter	clinical testing	Blueprint Genetics	Sep 08, 2017	- -

Hypertrophic cardiomyopathy

Pathogenic:2

Likely pathogenic, no assertion criteria provided	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Feb 08, 2013	proposed classification - variant undergoing re-assessment, contact laboratory -
Likely pathogenic, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Sep 18, 2023	This missense variant replaces phenylalanine with leucine at codon 110 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). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in several individuals affected with hypertrophic cardiomyopathy (PMID: 14636924, 23074333, 27532257, 29875424, 23074333, 27532257, 29875424, 35514357). It has been shown that this variant segregates with disease in 3 affected individuals in one family (PMID: 14636924, 16858239, 18533079). This variant has also been reported in an individual affected with hypertrophic cardiomyopathy and left ventricular systolic dysfunction who also carried a pathogenic variant in the MYBPC3 gene (PMID: 32228044). This variant has been identified in 2/251494 chromosomes in the general population by the Genome Aggregation Database (gnomAD). A different variant affecting the same codon, p.Phe110Ile, is considered to be disease-causing (ClinVar variation ID: 12412), suggesting that phenylalanine at this position is important for TNNT2 protein function. Based on the available evidence, this variant is classified as Likely Pathogenic. -

Dilated cardiomyopathy 1D

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Hypertrophic cardiomyopathy;C0043202:Wolff-Parkinson-White pattern

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

research

Agnes Ginges Centre for Molecular Cardiology, Centenary Institute

Feb 09, 2018

TNNT2 Phe110Leu had been previously identified in multiple HCM probands (Walsh R, et al., 2017; Coppini R, et al., 2014; GeneDx, Pers. Comm.) and in one family it was found to segregate to two affected family members (Torricelli F, et al., 2003). We identified this variant in 1 HCM proband and an affected parent. The proband also harbours a second mutation MYBPC3 p.Gly531Arg. The TNNT2 Phe110Leu variant is absent in the Genome Aggregation Database (http://gnomad.broadinstitute.org/). In silico tools SIFT, PolyPhen-2 and MutationTaster predict that this variant is deleterious. In summary, the variant has been reported in numerous cases, it is very rare in the general population, in silico tools predict the variant to impact protein function and the variant has segregated with disease in one family, therefore we classify TNNT2 Phe110Leu as 'Likely Pathogenic'. -

Cardiomyopathy

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Jul 27, 2023

This missense variant replaces phenylalanine with leucine at codon 110 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). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in several individuals affected with hypertrophic cardiomyopathy (PMID: 14636924, 23074333, 27532257, 29875424, 23074333, 27532257, 29875424, 35514357). It has been shown that this variant segregates with disease in 3 affected individuals in one family (PMID: 14636924, 16858239, 18533079). This variant has also been reported in an individual affected with hypertrophic cardiomyopathy and left ventricular systolic dysfunction who also carried a pathogenic variant in the MYBPC3 gene (PMID: 32228044). This variant has been identified in 2/251494 chromosomes in the general population by the Genome Aggregation Database (gnomAD). A different variant affecting the same codon, p.Phe110Ile, is considered to be disease-causing (ClinVar variation ID: 12412), suggesting that phenylalanine at this position is important for TNNT2 protein function. Based on the available evidence, this variant is classified as Likely Pathogenic. -

Cardiomyopathy, familial restrictive, 3

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Primary familial hypertrophic cardiomyopathy

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Jul 24, 2017

- -

Hypertrophic cardiomyopathy 2

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

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

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 21, 2024

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 110 of the TNNT2 protein (p.Phe110Leu). This variant is present in population databases (rs727504331, gnomAD 0.004%). This missense change has been observed in individuals with hypertrophic cardiomyopathy (PMID: 14636924, 25524337). ClinVar contains an entry for this variant (Variation ID: 177807). 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%. Experimental studies have shown that this missense change affects TNNT2 function (PMID: 33025817). This variant disrupts the p.Phe110 amino acid residue in TNNT2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9714088, 16115869, 33025817). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

CardioboostCm

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.44

BayesDel_noAF

Pathogenic

0.39

CADD

Benign

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.93

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

Eigen

Uncertain

0.20

Eigen_PC

Benign

-0.0043

FATHMM_MKL

Uncertain

0.82

LIST_S2

Uncertain

0.92

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

M_CAP

Pathogenic

0.70

MetaRNN

Pathogenic

0.89

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

MetaSVM

Uncertain

0.72

MutationAssessor

Pathogenic

3.1

.;.;.;M;.;.;.;.;.;.

MutationTaster

Benign

1.0

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

PrimateAI

Pathogenic

0.80

PROVEAN

Pathogenic

-5.7

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

REVEL

Pathogenic

0.80

Sift

Pathogenic

0.0

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

Sift4G

Benign

0.065

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

Polyphen

1.0, 1.0

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

Vest4

0.91

MutPred

0.39

.;.;.;Loss of methylation at K125 (P = 0.0775);.;.;.;.;.;Loss of methylation at K125 (P = 0.0775);

MVP

0.93

MPC

1.5

ClinPred

1.0

GERP RS

-3.8

Varity_R

0.81

gMVP

0.98

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