rs1553282484

Positions:

• chr1-201365238-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_001276345.2(TNNT2):​c.364A>G​(p.Asn122Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. 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 (★). Synonymous variant affecting the same amino acid position (i.e. N122N) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TNNT2 NM_001276345.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.26

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 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, 12 uncertain in NM_001276345.2
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.39229864).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TNNT2	NM_001276345.2	c.364A>G	p.Asn122Asp	missense_variant	10/17	ENST00000656932.1	NP_001263274.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TNNT2	ENST00000656932.1	c.364A>G	p.Asn122Asp	missense_variant	10/17		NM_001276345.2	ENSP00000499593.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 15, 2018

This sequence change replaces asparagine with aspartic acid at codon 112 of the TNNT2 protein (p.Asn112Asp). The asparagine residue is moderately conserved and there is a small physicochemical difference between asparagine and aspartic acid. This variant is not present in population databases (ExAC no frequency). 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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with TNNT2-related disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
CardioboostCm	Uncertain	0.10
BayesDel_addAF	Benign	-0.016	T
BayesDel_noAF	Benign	-0.26
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.59	.;.;.;D;.;.;.;.;D;.
Eigen	Benign	0.12
Eigen_PC	Uncertain	0.23
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.94	.;D;D;D;D;D;.;D;.;.
M_CAP	Uncertain	0.19	D
MetaRNN	Benign	0.39	T;T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.39	D
MutationAssessor	Benign	1.0	.;.;.;L;.;.;.;.;.;.
PrimateAI	Uncertain	0.68	T
PROVEAN	Benign	-0.74	N;N;.;.;.;.;.;N;N;N
REVEL	Uncertain	0.32
Sift	Benign	0.43	T;T;.;.;.;.;.;T;T;T
Sift4G	Benign	0.13	T;T;T;T;T;T;T;T;.;T
Polyphen		0.66, 0.77	.;.;.;P;.;.;.;.;P;.
Vest4		0.36
MutPred		0.34		.;.;.;Loss of methylation at K125 (P = 0.0676);.;.;.;.;.;Loss of methylation at K125 (P = 0.0676);
MVP		0.92
MPC		1.3
ClinPred		0.83	D
GERP RS		5.0
Varity_R		0.59
gMVP		0.51

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: rs1553282484; hg19: chr1-201334366;