dbSNP rs727505233: TNNT2:p.Gly289Glu (chr1-201359241-C-T) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1PM2

The NM_001276345.2(TNNT2):c.866G>A(p.Gly289Glu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G289R) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

TNNT2
NM_001276345.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 5.38

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:

ENSG00000286600 (HGNC:):

ENSG00000286600 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_001276345.2

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNT2	NM_001276345.2 link	c.866G>A	p.Gly289Glu	missense_variant	Exon 17 of 17	ENST00000656932.1	NP_001263274.1	P45379-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TNNT2	ENST00000656932.1 link	c.866G>A	p.Gly289Glu	missense_variant	Exon 17 of 17		NM_001276345.2	ENSP00000499593.1		P45379-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

1459176

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

725428

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:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:2

Aug 14, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant classified as Uncertain Significance - Favor Pathogenic. The Gly279Glu v ariant in TNNT2 has not been reported in individuals with cardiomyopathy or in l arge population studies. This variant was predicted to be pathogenic using a com putational tool clinically validated by our laboratory. This tool's pathogenic p rediction is estimated to be correct 94% of the time (Jordan 2011). In summary, while there is some suspicion for a pathogenic role, the clinical significance o f the Gly279Glu variant is uncertain. -

Mar 05, 2015

Stanford Center for Inherited Cardiovascular Disease, Stanford University

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. p.Gly279Glu (c.836T>A) in the TNNT2 gene (NM_001001430.1) The variant has been seen in at least one case of HCM (not including this patient's family). LMM has reported this variant in clinvar in one individual with HCM (at the time of review). They report the following: "The Gly279Glu variant in TNNT2 has not been reported in individuals with cardiomyopathy or in large population studies. This variant was predicted to be pathogenic using a computational tool clinically validated by our laboratory. This tool's pathogenic prediction is estimated to be correct 94% of the time (Jordan 2011). In summary, while there is some suspicion for a pathogenic role, the clinical significance of the Gly279Glu variant is uncertain." In silico analysis with HCM PolyPhen-2 predicts the variant to be pathogenic. The Gly at codon 279 is conserved across species, as are neighboring amino acids. Other variants have been reported in association with disease at nearby codons (R278C, R278P, R278H, K280N, R286C, R286P, R286H). In total the variant has not been seen in published controls and individuals from publicly available population datasets. There is no variation at codon 1836 listed in the NHLBI Exome Sequencing Project dataset, which currently includes variant calls on 6500 Caucasian and African American individuals (as of April 8, 2015). Note that this dataset does not match the patient's ancestry (Indian). There is one individual with variation at codon 279 listed in the Exome Aggregation Consortium dataset (http://exac.broadinstitute.org/), which currently includes variant calls on ~64,000 individuals of European, African, Latino and Asian descent (as of April 8, 2015). There also happens to be missense variation at codon 278 (42 individuals with missense variants). -

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

Sep 13, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Has not been previously published as pathogenic or benign to our knowledge; Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Reported in ClinVar as a variant of uncertain significance (ClinVar Variant ID# 179939; Landrum et al., 2016) -

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

- -

Hypertrophic cardiomyopathy 2

Uncertain:1

Apr 11, 2023

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Uncertain:1

Mar 12, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This sequence change replaces glycine with glutamic acid at codon 279 of the TNNT2 protein (p.Gly279Glu). The glycine residue is weakly conserved and there is a moderate physicochemical difference between glycine and glutamic acid. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with TNNT2-related conditions. ClinVar contains an entry for this variant (Variation ID: 179939). 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

0.98

CardioboostCm

Benign

0.085

BayesDel_addAF

Pathogenic

0.19

BayesDel_noAF

Uncertain

0.030

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.79

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

Eigen

Uncertain

0.64

Eigen_PC

Uncertain

0.56

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.96

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

M_CAP

Pathogenic

0.74

MetaRNN

Uncertain

0.60

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

MetaSVM

Uncertain

0.37

MutationAssessor

Benign

1.9

.;.;.;.;L;.;.;.;.;.

PrimateAI

Uncertain

0.76

PROVEAN

Uncertain

-4.2

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

REVEL

Uncertain

0.51

Sift

Pathogenic

0.0

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

Sift4G

Uncertain

0.0030

D;D;D;T;D;T;D;T;T;D

Polyphen

1.0

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

Vest4

0.58

MutPred

0.22

.;.;.;.;Loss of methylation at R288 (P = 0.0388);.;.;.;.;.;

MVP

0.94

MPC

1.6

ClinPred

0.99

GERP RS

4.0

Varity_R

0.37

gMVP

0.46

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

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