rs727504331

Variant summary

Our verdict is Pathogenic. Variant got 20 ACMG points: 20P and 0B. PS1PM1PM2PM5PP3_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 nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F120V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TNNT2
NM_001276345.2 missense

Scores

12
5
3

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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 20 ACMG points.

PS1
Transcript NM_001276345.2 (TNNT2) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar as 235064
PM1
In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain 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 chr1-201365244-A-T is described in ClinVar as [Pathogenic]. Clinvar id is 12412.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
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 rank MANE Protein UniProt
TNNT2NM_001276345.2 linkc.360T>G p.Phe120Leu missense_variant Exon 10 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.360T>G p.Phe120Leu missense_variant Exon 10 of 17 NM_001276345.2 ENSP00000499593.1 P45379-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000795
AC:
2
AN:
251494
Hom.:
0
AF XY:
0.00
AC XY:
0
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:
1
AN:
1461888
Hom.:
0
Cov.:
30
AF XY:
0.00
AC XY:
0
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.:
32

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
Sep 08, 2017
Blueprint Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Oct 09, 2023
GeneDx
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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) -

Hypertrophic cardiomyopathy Pathogenic:2
Sep 18, 2023
All of Us Research Program, National Institutes of Health
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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. -

Feb 08, 2013
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

proposed classification - variant undergoing re-assessment, contact laboratory -

Hypertrophic cardiomyopathy 2 Pathogenic:2
Apr 11, 2023
Genome-Nilou Lab
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 09, 2018
Agnes Ginges Centre for Molecular Cardiology, Centenary Institute
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: research

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'. -

Dilated cardiomyopathy 1D Pathogenic:1
Apr 11, 2023
Genome-Nilou Lab
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Cardiomyopathy Pathogenic:1
Mar 05, 2024
Color Diagnostics, LLC DBA Color Health
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces phenylalanine with leucine at codon 110 in the tropomyosin binding domain of the TNNT2 protein. Computational prediction tools indicate that this variant has a deleterious impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in at least seven individuals affected with hypertrophic cardiomyopathy (PMID: 14636924, 23074333, 27532257, 29875424, 23074333, 27532257, 29875424, 35514357, 37089884). It has been shown that this variant segregates with disease in three affected individuals in one family (PMID: 14636924, 16858239, 18533079). This variant has also been reported in one 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
Apr 11, 2023
Genome-Nilou Lab
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Primary familial hypertrophic cardiomyopathy Pathogenic:1
Jul 24, 2017
Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dilated cardiomyopathy 1D;C1861864:Hypertrophic cardiomyopathy 2;C2676271:Cardiomyopathy, familial restrictive, 3 Pathogenic:1
Nov 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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, 36578016). ClinVar contains an entry for this variant (Variation ID: 177807). 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on TNNT2 protein function. 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
D
BayesDel_noAF
Pathogenic
0.39
CADD
Benign
22
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.93
.;.;.;D;.;.;.;.;D;.
Eigen
Uncertain
0.20
Eigen_PC
Benign
-0.0043
FATHMM_MKL
Uncertain
0.82
D
LIST_S2
Uncertain
0.92
.;D;D;D;D;D;.;D;.;.
M_CAP
Pathogenic
0.70
D
MetaRNN
Pathogenic
0.89
D;D;D;D;D;D;D;D;D;D
MetaSVM
Uncertain
0.72
D
MutationAssessor
Pathogenic
3.1
.;.;.;M;.;.;.;.;.;.
PrimateAI
Pathogenic
0.80
T
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
D
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.

Other links and lift over

dbSNP: rs727504331; hg19: chr1-201334370; API