rs397516450
Variant summary
Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM1BP4
The NM_001276345.2(TNNT2):āc.248A>Gā(p.Asn83Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000991 in 1,613,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N83H) has been classified as Uncertain significance.
Frequency
Consequence
NM_001276345.2 missense
Scores
Clinical Significance
Conservation
Publications
- dilated cardiomyopathyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- dilated cardiomyopathy 1DInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
- hypertrophic cardiomyopathyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- hypertrophic cardiomyopathy 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- hypertrophic cardiomyopathy 3Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
- cardiomyopathy, familial restrictive, 3Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- familial isolated dilated cardiomyopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- familial isolated restrictive cardiomyopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- left ventricular noncompactionInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- cardiomyopathyInheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
- arrhythmogenic right ventricular cardiomyopathyInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 1 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| TNNT2 | NM_001276345.2 | c.248A>G | p.Asn83Ser | missense_variant | Exon 9 of 17 | ENST00000656932.1 | NP_001263274.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| TNNT2 | ENST00000656932.1 | c.248A>G | p.Asn83Ser | missense_variant | Exon 9 of 17 | NM_001276345.2 | ENSP00000499593.1 |
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152176Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 250952 AF XY: 0.0000295 show subpopulations
GnomAD4 exome AF: 0.00000684 AC: 10AN: 1461700Hom.: 0 Cov.: 31 AF XY: 0.00000825 AC XY: 6AN XY: 727114 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000394 AC: 6AN: 152176Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74328 show subpopulations
ClinVar
Submissions by phenotype
Dilated cardiomyopathy 1D;C1861864:Hypertrophic cardiomyopathy 2;C2676271:Cardiomyopathy, familial restrictive, 3 Uncertain:3
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TNNT2 NM_001001430.2 exon 8 p.Asn73Ser (c.218A>G): This variant has been reported in the literature in at least 1 individual with dilated cardiomyopathy (DCM) (Lakdawala 2012 PMID:22464770). This variant is present in 1/17246 East Asian alleles in the Genome Aggregation Database (http://gnomad.broadinstitute.org/rs397516450). This variant is present in ClinVar (Variation ID:43618). Evolutionary conservation and computational predictive tools suggest that this variant may impact the protein. In summary, data on this variant is insufficient for disease classification. Therefore, the clinical significance of this variant is uncertain. -
This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 73 of the TNNT2 protein (p.Asn73Ser). This variant is present in population databases (rs397516450, gnomAD 0.006%). This missense change has been observed in individual(s) with dilated cardiomyopathy (PMID: 22464770, 31737537). ClinVar contains an entry for this variant (Variation ID: 43618). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt TNNT2 protein function with a positive predictive value of 95%. 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. -
Cardiomyopathy Uncertain:2
This missense variant replaces asparagine with serine at codon 73 of the TNNT2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in at least 2 individuals affected with dilated cardiomyopathy (PMID: 22464770, 31737537). This variant has been identified in 6/250952 chromosomes 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. -
This missense variant replaces asparagine with serine at codon 73 of the TNNT2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with dilated cardiomyopathy (PMID: 22464770, 31737537). This variant has been identified in 6/250952 chromosomes 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. -
Dilated cardiomyopathy 1D Pathogenic:1
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not specified Uncertain:1
Needs reassessment: Evidence points to VUS -
Cardiovascular phenotype Uncertain:1
The p.N73S variant (also known as c.218A>G), located in coding exon 7 of the TNNT2 gene, results from an A to G substitution at nucleotide position 218. The asparagine at codon 73 is replaced by serine, an amino acid with highly similar properties. This variant was detected in one individual from a dilated cardiomyopathy cohort; however, clinical details were limited (Lakdawala NK et al. J. Card. Fail., 2012 Apr;18:296-303). This variant has also been reported in an exome cohort (Kurzlechner LM et al. J Pers Med, 2022 Apr;12:). This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at