rs727504243

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000363.5(TNNI3):​c.610C>T​(p.Arg204Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,170 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R204H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

TNNI3
NM_000363.5 missense

Scores

15
4
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5U:1

Conservation

PhyloP100: 1.60

Publications

10 publications found
Variant links:
Genes affected
TNNI3 (HGNC:11947): (troponin I3, cardiac type) Troponin I (TnI), along with troponin T (TnT) and troponin C (TnC), is one of 3 subunits that form the troponin complex of the thin filaments of striated muscle. TnI is the inhibitory subunit; blocking actin-myosin interactions and thereby mediating striated muscle relaxation. The TnI subfamily contains three genes: TnI-skeletal-fast-twitch, TnI-skeletal-slow-twitch, and TnI-cardiac. This gene encodes the TnI-cardiac protein and is exclusively expressed in cardiac muscle tissues. Mutations in this gene cause familial hypertrophic cardiomyopathy type 7 (CMH7) and familial restrictive cardiomyopathy (RCM). Troponin I is useful in making a diagnosis of heart failure, and of ischemic heart disease. An elevated level of troponin is also now used as indicator of acute myocardial injury in patients hospitalized with moderate/severe Coronavirus Disease 2019 (COVID-19). Such elevation has also been associated with higher risk of mortality in cardiovascular disease patients hospitalized due to COVID-19. [provided by RefSeq, Aug 2020]
TNNI3 Gene-Disease associations (from GenCC):
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • dilated cardiomyopathy 2A
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • hypertrophic cardiomyopathy 7
    Inheritance: AR, AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
  • cardiomyopathy, familial restrictive, 1
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • dilated cardiomyopathy 1FF
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • dilated cardiomyopathy
    Inheritance: AD Classification: MODERATE Submitted by: ClinGen
  • familial isolated dilated cardiomyopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • familial isolated restrictive 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: Pathogenic. The variant received 18 ACMG points.

PM1
In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 27 uncertain in NM_000363.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr19-55151856-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 177679.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.977
PP5
Variant 19-55151857-G-A is Pathogenic according to our data. Variant chr19-55151857-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 177631.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TNNI3NM_000363.5 linkc.610C>T p.Arg204Cys missense_variant Exon 8 of 8 ENST00000344887.10 NP_000354.4 P19429Q6FGX2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TNNI3ENST00000344887.10 linkc.610C>T p.Arg204Cys missense_variant Exon 8 of 8 1 NM_000363.5 ENSP00000341838.5 P19429

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152170
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.00
GnomAD4 exome
Cov.:
31
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152170
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74342
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41432
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
May 16, 2025
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Published functional studies demonstrate increased calcium sensitivity compared to wild type (PMID: 27895589); Reported in association with HCM in the published literature and reported in patients with HCM referred for genetic testing at GeneDx (PMID: 15524171, 12860912, 27532257); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 12860912, 26199943, 27532257, 30165862, 33906374, 34036930, 36252119, 35838873, 37652022, 15524171, 27895589) -

-
Stanford Center for Inherited Cardiovascular Disease, Stanford University
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. p.Arg204Cys (c.610 C>T) in the TNNI3 gene. This variant has been reported online in one case of HCM (http://cardiogenomics.med.harvard.edu). It has also been seen by another genetic testing laboratory, in two individuals with a clinical diagnosis of restrictive cardiomyopathy (verbal report). None of these cases have been reported in the literature (though reviews and compendiums do refer to this variant). Another variant at the same codon has been reported in association with both HCM and RCM (p.Arg204His, Kimura et al 1997, Koga et al 1996, Doolan et al 2005). In addition, multiple variants have been reported at nearby codons (p.Glu202Gly, p.Gly203Arg, p.Gly203Ser, p.Lys205Gln, see Willot et al 2010 review). The Arginine at codon 204 is completely conserved across species as are the neighboring amino acids. In silico analysis (PolyPhen2) predicts the variant to be probably damaging. The testing lab noted that the variant was absent in 100 Caucasian individuals and 100 African-American individuals. -

Cardiomyopathy Pathogenic:1
Oct 19, 2020
Victorian Clinical Genetics Services, Murdoch Childrens Research Institute
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Based on the classification scheme VCGS_Germline_v1.1.1, this variant is classified as Pathogenic. Following criteria are met: 0103 - Both loss- and gain-of-function are known mechanisms of disease for this gene. Missense variants functionally proven to cause a loss of function effect by decreasing calcium sensitivity cause dilated cardiomyopathy (DCM). Missense variants functionally proven to cause a gain of function effect by increasing calcium sensitivity cause hypertrophic cardiomyopathy (HCM) (PMID: 21533915). (N) 0108 - This gene is known to be associated with both recessive and dominant disease. Only a single family has been reported with a recessive form of inheritance (OMIM). (N) 0112 - Variants in this gene are known to have reduced penetrance (PMID: 15607392). (N) 0200 - Variant is predicted to result in a missense amino acid change from arginine to histidine (exon 8). (N) 0251 - Variant is heterozygous. (N) 0301 - Variant is absent from gnomAD. (P) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (1 heterozygote, 0 homozygotes). (N) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (P) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (N) 0704 - Comparable variant has low previous evidence for pathogenicity. An alternative missense change at the same residue (p.Arg204Cys) has been reported as pathogenic, and observed in patients with restrictive cardiomyopathy (RCM) and HCM (ClinVar, PMID: 27895589). (P) 0801 - Strong previous evidence of pathogenicity in unrelated individuals. This variant has been reported as pathogenic, and reported in multiple patients with HCM, RCM and infantile ventricular septal defects (ClinVar, PMID: 27895589, PMID: 31912959, PMID: 20569525). Some of these reports were de novo. (P) 1002 - Moderate functional evidence supporting abnormal protein function. Analysis of animal model muscle fibres found this variant results in increased calcium sensitivity and reduced interactions with Troponins C and T (PMID: 27895589). (P) 1208 - Inheritance information for this variant is not currently available. (N) Legend: (P) - Pathogenic, (N) - Neutral, (B) - Benign -

Hypertrophic cardiomyopathy Pathogenic:1
May 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 204 of the TNNI3 protein (p.Arg204Cys). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with clinical features of autosomal dominant TNNI3-related conditions and/or dilated cardiomyopathy, restrictive cardiomyopathy (PMID: 30165862, 33906374, 34036930, 36252119; Invitae). ClinVar contains an entry for this variant (Variation ID: 177631). 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 TNNI3 function (PMID: 27895589). This variant disrupts the p.Arg204 amino acid residue in TNNI3. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15698845, 18801787, 20569525, 29176140). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

TNNI3-associated disorder Pathogenic:1
Jun 23, 2025
Institute of Human Genetics Munich, TUM University Hospital
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Feb 03, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:flagged submission
Collection Method:clinical testing

Variant classified as Uncertain Significance - Favor Pathogenic. The p.Arg204Cys variant in TNNI3 has been identified by our laboratory in 1 child with features of RCM and HCM and 1 child with RCM and Vfib. The variant was absent from large population studies. In vitro functional studies provide some evidence that the p.Arg204Cys variant may impact protein function (Cui 2013 [conference abstract]) . However, these types of assays may not accurately represent biological functio n. Additionally, a different amino acid alteration at this position (p.Arg204His ) is likely pathogenic and has also been identified in individuals with RCM and/ or HCM, supporting that a change at this position may not be tolerated. In summa ry, while there is some suspicion for a pathogenic role, the clinical significan ce of the p.Arg204Cys variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
CardioboostCm
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.36
D
BayesDel_noAF
Pathogenic
0.28
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.94
D;D
Eigen
Uncertain
0.61
Eigen_PC
Uncertain
0.53
FATHMM_MKL
Uncertain
0.88
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.69
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Uncertain
2.4
M;.
PhyloP100
1.6
PrimateAI
Pathogenic
0.81
D
PROVEAN
Pathogenic
-6.8
D;.
REVEL
Pathogenic
0.90
Sift
Pathogenic
0.0
D;.
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
D;.
Vest4
0.93
MutPred
0.87
Loss of MoRF binding (P = 0.0051);.;
MVP
1.0
MPC
2.0
ClinPred
1.0
D
GERP RS
3.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.83
Mutation Taster
=1/99
disease causing (ClinVar)

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: rs727504243; hg19: chr19-55663225; COSMIC: COSV52571349; COSMIC: COSV52571349; API