rs397516848

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 3P and 4B. PM1PP2BS2

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 (★★). Synonymous variant affecting the same amino acid position (i.e. I148I) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000013 ( 1 hom. )

Consequence

TNNC1
NM_003280.3 missense

Scores

2
4
13

Clinical Significance

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

Conservation

PhyloP100: 4.93

Publications

16 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 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, 19 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.
BS2
High AC in GnomAdExome4 at 19 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TNNC1NM_003280.3 linkc.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 Appris UniProt
TNNC1ENST00000232975.8 linkc.442A>G p.Ile148Val missense_variant Exon 5 of 6 1 NM_003280.3 ENSP00000232975.3 P63316
TNNC1ENST00000496590.1 linkc.*12A>G downstream_gene_variant 2 ENSP00000420596.1 C9JDI3
TNNC1ENST00000461086.1 linkn.*36A>G downstream_gene_variant 2

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152164
Hom.:
0
Cov.:
33
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
GnomAD2 exomes
AF:
0.00000797
AC:
2
AN:
250838
AF XY:
0.0000147
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:
0.00000883
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000130
AC:
19
AN:
1461864
Hom.:
1
Cov.:
31
AF XY:
0.0000110
AC XY:
8
AN XY:
727230
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000117
AC:
13
AN:
1111992
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
Heterozygous variant carriers
0
1
3
4
6
7
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152164
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74338
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41412
American (AMR)
AF:
0.0000655
AC:
1
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000230
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00000824
AC:
1
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
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. -

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. -

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
T
BayesDel_noAF
Benign
-0.19
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Benign
0.42
T
Eigen
Benign
-0.033
Eigen_PC
Benign
0.066
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.95
D
M_CAP
Benign
0.031
D
MetaRNN
Uncertain
0.55
D
MetaSVM
Benign
-0.58
T
MutationAssessor
Benign
1.5
L
PhyloP100
4.9
PrimateAI
Pathogenic
0.80
T
PROVEAN
Benign
-0.22
N
REVEL
Uncertain
0.34
Sift
Benign
0.46
T
Sift4G
Benign
0.84
T
Polyphen
0.30
B
Vest4
0.61
MutPred
0.63
Loss of catalytic residue at I148 (P = 0.1114);
MVP
0.63
MPC
1.2
ClinPred
0.40
T
GERP RS
5.3
Varity_R
0.57
gMVP
0.64
Mutation Taster
=45/55
disease causing

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

Other links and lift over

dbSNP: rs397516848; hg19: chr3-52485419; API