1-201359242-C-T

Position:

chr1-201359242-C-T

Variant summary

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

The NM_001276345.2(TNNT2):c.865G>A(p.Gly289Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000206 in 1,459,102 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G289E) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

TNNT2
NM_001276345.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 1.34

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 Uncertain_significance. Variant got 4 ACMG points.

PM1

In a hotspot region, there are 5 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;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNT2	NM_001276345.2 linkuse as main transcript	c.865G>A	p.Gly289Arg	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.865G>A	p.Gly289Arg	missense_variant	17/17		NM_001276345.2	A2	P45379-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000409

AC:

AN:

244698

Hom.:

AF XY:

0.00000757

AC XY:

AN XY:

132024

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:

0.00

Gnomad NFE exome

AF:

0.00000905

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000206

AC:

AN:

1459102

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

725352

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:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

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

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Apr 26, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 12, 2023	This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 279 of the TNNT2 protein (p.Gly279Arg). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with TNNT2-related conditions. ClinVar contains an entry for this variant (Variation ID: 426271). 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. 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. -

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

Apr 21, 2017

A variant of uncertain significance has been identified in the TNNT2 gene. The G279R variant has not been published as pathogenic or been reported as benign to our knowledge. This variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). The G279R variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. Additionally, this substitution occurs at a position that is conserved across species. Furthermore, in silico analysis predicts this variant is probably damaging to the protein structure/function. Nevertheless, the G279R variant lacks observation in a significant number of affected individuals, segregation data, and functional evidence, which would further clarify its pathogenicity. -

Cardiomyopathy, familial restrictive, 3

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Hypertrophic cardiomyopathy 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Apr 11, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.97

CardioboostCm

Benign

0.031

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Uncertain

-0.020

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.80

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

Eigen

Uncertain

0.55

Eigen_PC

Uncertain

0.46

FATHMM_MKL

Uncertain

0.86

LIST_S2

Uncertain

0.95

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

M_CAP

Pathogenic

0.73

MetaRNN

Uncertain

0.60

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

MetaSVM

Uncertain

0.34

MutationAssessor

Uncertain

2.2

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

MutationTaster

Benign

1.0

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

PrimateAI

Uncertain

0.77

PROVEAN

Uncertain

-3.2

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

REVEL

Uncertain

0.48

Sift

Uncertain

0.013

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

Sift4G

Uncertain

0.0030

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

Polyphen

1.0

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

Vest4

0.59

MutPred

0.25

.;.;.;.;Gain of methylation at G289 (P = 0.0239);.;.;.;.;.;

MVP

0.94

MPC

1.6

ClinPred

0.98

GERP RS

4.0

Varity_R

0.29

gMVP

0.45

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