rs1060500235

Positions:

• chr1-201365657-T-C
• chr1-201365657-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_001276345.2(TNNT2):​c.247A>G​(p.Asn83Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar 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: 1.56

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a chain Troponin T, cardiac muscle (size 296) in uniprot entity TNNT2_HUMAN there are 88 pathogenic changes around while only 9 benign (91%) in NM_001276345.2
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TNNT2	NM_001276345.2	c.247A>G	p.Asn83Asp	missense_variant	9/17	ENST00000656932.1	NP_001263274.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TNNT2	ENST00000656932.1	c.247A>G	p.Asn83Asp	missense_variant	9/17		NM_001276345.2	ENSP00000499593	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

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

Jun 21, 2016

In summary, this variant is a novel missense change with uncertain impact on protein function. 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 is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a TNNT2-related disease. This sequence change replaces asparagine with aspartic acid at codon 73 of the TNNT2 protein (p.Asn73Asp). The asparagine residue is highly conserved and there is a small physicochemical difference between asparagine and aspartic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.46
CardioboostCm	Uncertain	0.71
BayesDel_addAF	Uncertain	0.11	D
BayesDel_noAF	Uncertain	-0.070
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.70	.;.;.;.;D;.;.;.;.;.;T;.;.;T
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Uncertain	0.87	.;D;D;D;D;D;D;.;.;D;.;.;D;.
M_CAP	Pathogenic	0.75	D
MetaRNN	Uncertain	0.52	D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	.;.;.;.;M;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.63	T
PROVEAN	Benign	-1.9	N;N;.;.;.;.;.;.;N;N;N;N;N;N
REVEL	Uncertain	0.52
Sift	Uncertain	0.028	D;D;.;.;.;.;.;.;D;D;D;D;D;D
Sift4G	Benign	0.16	T;T;T;T;T;T;T;T;T;T;.;T;T;.
Polyphen		0.99, 0.99	.;.;.;.;D;.;.;.;.;.;D;.;.;.
Vest4		0.45
MutPred		0.11		.;.;.;.;Gain of glycosylation at K88 (P = 0.1838);.;.;.;.;.;.;Gain of glycosylation at K88 (P = 0.1838);.;.;
MVP		0.97
MPC		1.4
ClinPred		0.93	D
GERP RS		4.7
Varity_R		0.23
gMVP		0.67

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: rs1060500235; hg19: chr1-201334785;