chr3-52451292-T-G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 3P and 6B. PM1PP2BP4_ModerateBS2

The NM_003280.3(TNNC1):c.469A>C(p.Met157Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000929 in 1,613,904 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 Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M157I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

TNNC1
NM_003280.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.35

Publications

1 publications found

Variant links:

Genes affected

TNNC1 (HGNC:11943): (troponin C1, slow skeletal and cardiac type) Troponin is a central regulatory protein of striated muscle contraction, and together with tropomyosin, is located on the actin filament. Troponin consists of 3 subunits: TnI, which is the inhibitor of actomyosin ATPase; TnT, which contains the binding site for tropomyosin; and TnC, the protein encoded by this gene. The binding of calcium to TnC abolishes the inhibitory action of TnI, thus allowing the interaction of actin with myosin, the hydrolysis of ATP, and the generation of tension. Mutations in this gene are associated with cardiomyopathy dilated type 1Z. [provided by RefSeq, Oct 2008]

TNNC1 Gene-Disease associations (from GenCC):

dilated cardiomyopathy
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
dilated cardiomyopathy 1Z
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
hypertrophic cardiomyopathy
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
hypertrophic cardiomyopathy 13
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, G2P
familial isolated dilated cardiomyopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
arrhythmogenic right ventricular cardiomyopathy
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

TNNC1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_003280.3

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 11 curated pathogenic missense variants (we use a threshold of 10). The gene has 0 curated benign missense variants. Gene score misZ: 1.7682 (below the threshold of 3.09). Trascript score misZ: 2.6866 (below the threshold of 3.09). GenCC associations: The gene is linked to hypertrophic cardiomyopathy 13, dilated cardiomyopathy 1Z, familial isolated dilated cardiomyopathy, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy.

BP4

Computational evidence support a benign effect (MetaRNN=0.253663).

BS2

High AC in GnomAdExome4 at 14 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNC1	NM_003280.3 link	c.469A>C	p.Met157Leu	missense_variant	Exon 6 of 6	ENST00000232975.8	NP_003271.1	P63316Q6FH91

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
TNNC1	ENST00000232975.8 link	c.469A>C	p.Met157Leu	missense_variant	Exon 6 of 6	1	NM_003280.3	ENSP00000232975.3	P63316
TNNC1	ENST00000496590.1 link	c.*123A>C		downstream_gene_variant		2		ENSP00000420596.1	C9JDI3
TNNC1	ENST00000461086.1 link	n.*147A>C		downstream_gene_variant		2

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152068

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.000478

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251070

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000882

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000958

AC:

AN:

1461836

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727210

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53384

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000126

AC:

AN:

1111998

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.496

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152068

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74280

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41394

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67986

Other (OTH)

AF:

0.000478

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000113

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Dilated cardiomyopathy 1Z;C2750472:Hypertrophic cardiomyopathy 13

Uncertain:1

Apr 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 157 of the TNNC1 protein (p.Met157Leu). This variant is present in population databases (rs730880230, gnomAD 0.0009%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 29121657). ClinVar contains an entry for this variant (Variation ID: 181569). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

not provided

Uncertain:1

Mar 06, 2017

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This variant is denoted p.Met157Leu (ATG>CTG): c.469 A>C in exon 6 of the TNNC1 gene (NM_003280.2). Mutations in the TNNC1 gene are a rare cause of autosomal dominant familial hypertrophic cardiomyopathy (HCM) and are thought to change calcium sensitivity and heart muscle contraction (Cirino A et al., 2011). Mutation in the TNNC1 gene been reported less frequently in patients with autosomal dominant dilated cardiomyopathy (DCM) (Morgensen J et al., 2004; Hershberger R et al., 2010). The M157L variant has not been published as a mutation or as a benign polymorphism to our knowledge. The M157L variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. While the M157L variant is a conservative amino acid substitution, which is not likely to impact secondary protein structure as these residues share similar properties, this substitution occurs at a position that is conserved in mammals. In silico analysisis inconsistent in its predictions, however at least two models predict this variant is probably damaging to the protein structure/function. A missense mutation in a nearby residue (G159D) has been reported in association with DCM, supporting the functional importance of this region of the protein. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic mutation or a rare benign variant. The variant is found in CARDIOMYOPATHY panel(s). -

Cardiovascular phenotype

Uncertain:1

Oct 18, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.M157L variant (also known as c.469A>C), located in coding exon 6 of the TNNC1 gene, results from an A to C substitution at nucleotide position 469. The methionine at codon 157 is replaced by leucine, an amino acid with highly similar properties. This variant was detected in a hypertrophic cardiomyopathy cohort; however, details were not provided (Viswanathan SK et al. PLoS ONE. 2017;12:e0187948). This alteration was also identified in a subject suspected to have arrhythmogenic right ventricular cardiomyopathy (ARVC) (Forleo C et al. PLoS One, 2017 Jul;12:e0181842). 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: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.46

BayesDel_addAF

Uncertain

0.095

BayesDel_noAF

Benign

-0.10

CADD

Uncertain

(source)

DANN

Uncertain

0.98

DEOGEN2

Uncertain

0.55

Eigen

Benign

0.032

Eigen_PC

Benign

0.13

FATHMM_MKL

Benign

0.75

LIST_S2

Uncertain

0.92

M_CAP

Uncertain

0.12

MetaRNN

Benign

0.25

MetaSVM

Uncertain

0.42

MutationAssessor

Benign

0.53

PhyloP100

3.4

PrimateAI

Uncertain

0.72

PROVEAN

Benign

-1.8

REVEL

Uncertain

0.44

Sift

Uncertain

0.027

Sift4G

Benign

0.076

Polyphen

0.067

Vest4

0.36

MutPred

0.54

Loss of disorder (P = 0.0738);

MVP

0.58

MPC

1.0

ClinPred

0.73

GERP RS

2.5

Varity_R

0.73

gMVP

0.79

Mutation Taster

=48/52

disease causing

(source)

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

Publications

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chr3-52451292-T-G

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over