NM_001276345.2:c.565T>G

Variant names:

• chr1-201363331-A-C
• rs377157235
• NM_001276345.2:c.565T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM5 PP5_Moderate

The NM_001276345.2(TNNT2):​c.565T>G​(p.Ser189Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. S189F) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: TNNT2 NM_001276345.2 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 5.16
• Publications: 2 publications found

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

ENSG00000286600 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 32 uncertain in NM_001276345.2
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-201363330-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 177634.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP5: Variant 1-201363331-A-C is Pathogenic according to our data. Variant chr1-201363331-A-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 469526.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNT2	NM_001276345.2	c.565T>G	p.Ser189Ala	missense_variant	Exon 12 of 17	ENST00000656932.1	NP_001263274.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TNNT2	ENST00000656932.1	c.565T>G	p.Ser189Ala	missense_variant	Exon 12 of 17		NM_001276345.2	ENSP00000499593.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461890 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727248

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000629 AC: 7 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Jan 27, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 179 of the TNNT2 protein (p.Ser179Ala). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of hypertrophic cardiomyopathy (internal data). ClinVar contains an entry for this variant (Variation ID: 469526). 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%. This variant disrupts the p.Ser179 amino acid residue in TNNT2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11034944, 27532257). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
CardioboostCm	Benign	0.015
BayesDel_addAF	Uncertain	0.056	T
BayesDel_noAF	Benign	-0.16
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.67	.;.;.;.;D;.;.;.;.;.;D
Eigen	Uncertain	0.45
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.88	.;D;D;D;D;D;D;.;.;D;.
M_CAP	Pathogenic	0.33	D
MetaRNN	Uncertain	0.65	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.16	D
MutationAssessor	Benign	1.6	.;.;.;.;L;.;.;.;.;.;.
PhyloP100		5.2
PrimateAI	Uncertain	0.75	T
PROVEAN	Benign	-2.0	N;N;.;.;.;.;.;.;N;N;N
REVEL	Uncertain	0.53
Sift	Benign	0.067	T;T;.;.;.;.;.;.;T;T;T
Sift4G	Benign	0.22	T;T;T;T;T;T;T;T;T;T;.
Polyphen		0.97, 0.97	.;.;.;.;D;.;.;.;.;.;D
Vest4		0.56
MVP		0.94
MPC		1.3
ClinPred		0.91	D
GERP RS		4.9
Varity_R		0.25
gMVP		0.65
Mutation Taster		=74/26	polymorphism

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

Other links and lift over

dbSNP: rs377157235; hg19: chr1-201332459;