NM_003280.3:c.442A>G

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM1BS2

The NM_003280.3(TNNC1):c.442A>G(p.Ile148Val) variant causes a missense change. The variant allele was found at a frequency of 0.000013 in 1,614,028 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000013 ( 1 hom. )

Consequence

TNNC1
NM_003280.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 4.93

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM1

In a chain Troponin C, slow skeletal and cardiac muscles (size 160) in uniprot entity TNNC1_HUMAN there are 13 pathogenic changes around while only 0 benign (100%) in NM_003280.3

BS2

High AC in GnomAdExome4 at 19 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNC1	NM_003280.3 link	c.442A>G	p.Ile148Val	missense_variant	Exon 5 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.442A>G	p.Ile148Val	missense_variant	Exon 5 of 6	1	NM_003280.3	ENSP00000232975.3	P63316
TNNC1	ENST00000496590.1 link	c.*12A>G		downstream_gene_variant		2		ENSP00000420596.1	C9JDI3
TNNC1	ENST00000461086.1 link	n.*36A>G		downstream_gene_variant		2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152164

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000797

AC:

AN:

250838

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135792

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000883

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000130

AC:

AN:

1461864

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727230

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000117

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152164

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:2

May 25, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Ile148Val variant in TNNC1 has been identified in 1 individual with DCM and was absent from 492 control chromosomes (Hershberger 2010). Studies showed that this variant exhibited decreased calcium sensitivity and altered response to PKA phosphorylation, but these in vitro assays may not accurately represent biologi cal function (Pinto 2011). Computational analyses (biochemical amino acid proper ties, conservation,AlignGVGD, and SIFT) suggest that the Ile148Val variant may n ot impact the protein, though this information is not predictive enough to rule out pathogenicity. In summary, the available information for this variant is con flicting and additional information is needed to fully assess its clinical signi ficance. -

Jul 06, 2021

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TNNC1 c.442A>G (p.Ile148Val) results in a conservative amino acid change located in the EF-hand domain (IPR002048) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 250838 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.442A>G has been reported in the literature in individuals affected with Cardiomyopathy and SUD (e.g. Hershberger_2010, Pinto_2011, Ng_2013, Pugh_2014, Dewar_2017). These reports do not provide unequivocal conclusions about association of the variant with Cardiomyopathy. A co-occurrence with a likely pathogenic variant has been reported (DSP c.2848_2849insA, p.Ile950AsnfsX3; Pugh_2014). Experimental evidence evaluating an impact on protein function demonstrated pig skinned fibers reconstituted with the variant and incubated with PKA, to have a reduced effect of PKA phosphorylation on myofilament Ca2+ desensitization compared with WT. Nevertheless, the variant was similar to WT in fully activating or inhibiting the actomyosin ATPase activity in the presence and absence of Ca2+, while it did not affect the maximal force recovery in the presence or absence of PKA compared with WT (Pinto_2011). These data do not allow convincing conclusions about the variant effect. Two ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Dilated cardiomyopathy 1Z;C2750472:Hypertrophic cardiomyopathy 13

Uncertain:1

Sep 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 148 of the TNNC1 protein (p.Ile148Val). This variant is present in population databases (rs397516848, gnomAD 0.003%). This missense change has been observed in individual(s) with clinical features of dilated cardiomyopathy (PMID: 20215591, 24503780, 27532257, 28807990, 37652022). ClinVar contains an entry for this variant (Variation ID: 44682). 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. Experimental studies have shown that this missense change affects TNNC1 function (PMID: 21832052). 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. -

Primary dilated cardiomyopathy

Uncertain:1

Apr 05, 2018

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.31

BayesDel_addAF

Benign

-0.023

BayesDel_noAF

Benign

-0.19

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.42

Eigen

Benign

-0.033

Eigen_PC

Benign

0.066

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

M_CAP

Benign

0.031

MetaRNN

Uncertain

0.55

MetaSVM

Benign

-0.58

MutationAssessor

Benign

1.5

PrimateAI

Pathogenic

0.80

PROVEAN

Benign

-0.22

REVEL

Uncertain

0.34

Sift

Benign

0.46

Sift4G

Benign

0.84

Polyphen

0.30

Vest4

0.61

MutPred

0.63

Loss of catalytic residue at I148 (P = 0.1114);

MVP

0.63

MPC

1.2

ClinPred

0.40

GERP RS

5.3

Varity_R

0.57

gMVP

0.64

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over