1-201359214-T-C

Variant names:

• chr1-201359214-T-C
• rs770794082
• NM_001276345.2:c.893A>G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_001276345.2(TNNT2):​c.893A>G​(p.Lys298Arg) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 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. K298T) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TNNT2 NM_001276345.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.92

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]

ENSG00000286600 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a chain Troponin T, cardiac muscle (size 296) in uniprot entity TNNT2_HUMAN there are 176 pathogenic changes around while only 18 benign (91%) in NM_001276345.2
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.22610646).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNT2	NM_001276345.2	c.893A>G	p.Lys298Arg	missense_variant	Exon 17 of 17	ENST00000656932.1	NP_001263274.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TNNT2	ENST00000656932.1	c.893A>G	p.Lys298Arg	missense_variant	Exon 17 of 17		NM_001276345.2	ENSP00000499593.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiomyopathy Uncertain:1

May 30, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces lysine with arginine at codon 288 of the TNNT2 protein. Computational prediction tools indicate that this variant has a neutral impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TNNT2-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.33
CardioboostCm	Uncertain	0.20
BayesDel_addAF	Uncertain	0.032	T
BayesDel_noAF	Benign	-0.19
CADD	Uncertain	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.49	.;.;.;.;T;.;.;.;.;.
Eigen	Benign	0.11
Eigen_PC	Benign	0.14
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Uncertain	0.93	.;D;D;D;D;D;D;.;.;D
M_CAP	Uncertain	0.095	D
MetaRNN	Benign	0.23	T;T;T;T;T;T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.6	.;.;.;.;L;.;.;.;.;.
PrimateAI	Uncertain	0.69	T
PROVEAN	Benign	-1.1	N;N;N;.;.;D;.;.;N;N
REVEL	Benign	0.051
Sift	Pathogenic	0.0	D;D;T;.;.;D;.;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D;D;D
Polyphen		0.78	.;.;.;.;P;.;.;.;.;.
Vest4		0.43
MutPred		0.45		.;.;.;.;Gain of methylation at R296 (P = 0.0999);.;.;.;.;.;
MVP		0.65
MPC		1.3
ClinPred		0.78	D
GERP RS		4.0
Varity_R		0.047
gMVP		0.18

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

Other links and lift over

dbSNP: rs770794082; hg19: chr1-201328342;