rs397516477

Variant names:

• chr1-201372031-A-C
• rs397516477
• NM_001276345.2:c.63T>G

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Strong BP6 BP7 BS1

The NM_001276345.2(TNNT2):​c.63T>G​(p.Val21Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000582 in 1,597,574 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).

• Frequency:
  • Genomes: 𝑓 0.000029 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000061 (0 hom.)
• Consequence: TNNT2 NM_001276345.2 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:8
• Conservation: PhyloP100: -0.134
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1D

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• hypertrophic cardiomyopathy 3

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• cardiomyopathy, familial restrictive, 3

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated restrictive cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• left ventricular noncompaction

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• cardiomyopathy

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ENSG00000286600 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.82).
• BP6: Variant 1-201372031-A-C is Benign according to our data. Variant chr1-201372031-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 43660.
• BP7: Synonymous conserved (PhyloP=-0.134 with no splicing effect.
• BS1: Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.0000295 (4/135686) while in subpopulation EAS AF = 0.000859 (4/4656). AF 95% confidence interval is 0.000293. There are 0 homozygotes in GnomAd4. There are 2 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNT2	NM_001276345.2	c.63T>G	p.Val21Val	synonymous_variant	Exon 4 of 17	ENST00000656932.1	NP_001263274.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TNNT2	ENST00000656932.1	c.63T>G	p.Val21Val	synonymous_variant	Exon 4 of 17		NM_001276345.2	ENSP00000499593.1

Frequencies

GnomAD3 genomes AF: 0.0000295 AC: 4 AN: 135568 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000858

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000877 AC: 22 AN: 250798 AF XY: 0.000103

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00103

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000609 AC: 89 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.0000729 AC XY: 53 AN XY: 727244

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00194 AC: 77 AN: 39700

South Asian (SAS) AF: 0.000116 AC: 10 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112008

Other (OTH) AF: 0.0000331 AC: 2 AN: 60396

GnomAD4 genome AF: 0.0000295 AC: 4 AN: 135686 Hom.: 0 Cov.: 32 AF XY: 0.0000305 AC XY: 2 AN XY: 65664

African (AFR) AF: 0.00 AC: 0 AN: 39604

American (AMR) AF: 0.00 AC: 0 AN: 12208

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3090

East Asian (EAS) AF: 0.000859 AC: 4 AN: 4656

South Asian (SAS) AF: 0.00 AC: 0 AN: 3858

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 8296

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 270

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 61044

Other (OTH) AF: 0.00 AC: 0 AN: 1806

Alfa AF: 0.0000430 Hom.: 0

Bravo AF: 0.0000378

Asia WGS AF: 0.000866 AC: 3 AN: 3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:8

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Benign:2

Oct 29, 2018

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TNNT2 c.63T>G alters a non-conserved nucleotide resulting in a synonymous change. The variant allele was found at a frequency of 8.4e-05 in 273784 control chromosomes, predominantly at a frequency of 0.0011 within the East Asian subpopulation in the gnomAD database. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 6.29 fold of the estimated maximal expected allele frequency for a pathogenic variant in TNNT2 causing Cardiomyopathy phenotype (0.00018), strongly suggesting that the variant is a benign polymorphism found primarily in populations of East Asian origin. To our knowledge, no occurrence of c.63T>G in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as benign. -

Jul 22, 2010

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

p.Val21Val in exon 4 of TNNT2: This variant is not expected to have clinical sig nificance because it does not alter an amino acid residue and is not located wit hin the splice consensus sequence. -

Cardiomyopathy Benign:2

Oct 17, 2017

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 10, 2018

Color Diagnostics, LLC DBA Color Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Benign:2

-

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

-

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Cardiomyopathy, familial restrictive, 3 Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Hypertrophic cardiomyopathy 2 Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Cardiovascular phenotype Benign:1

Oct 05, 2023

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

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

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.82
CADD	Benign	4.4
DANN	Benign	0.84
PhyloP100		-0.13
Mutation Taster		=100/0	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs397516477; hg19: chr1-201341159;