19-55154082-G-C

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 6P and 1B. PM1PM2PM5BP4

The NM_000363.5(TNNI3):c.497C>G(p.Ser166Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000132 in 151,740 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 variant affecting the same amino acid position, but resulting in a different missense (i.e. S166P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)

Consequence

TNNI3
NM_000363.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 3.53

Publications

16 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

TNNI3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1

In a hotspot region, there are 14 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 18 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 chr19-55154082-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 177630.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP4

Computational evidence support a benign effect (MetaRNN=0.4162463).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNI3	NM_000363.5 link	c.497C>G	p.Ser166Cys	missense_variant	Exon 7 of 8	ENST00000344887.10	NP_000354.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TNNI3	ENST00000344887.10 link	c.497C>G	p.Ser166Cys	missense_variant	Exon 7 of 8	1	NM_000363.5	ENSP00000341838.5

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

151740

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000484

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.:

GnomAD4 genome

AF:

0.0000132

AC:

AN:

151740

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74090

show subpopulations

African (AFR)

AF:

0.0000484

AC:

AN:

41292

American (AMR)

AF:

0.00

AC:

AN:

15240

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5144

South Asian (SAS)

AF:

0.00

AC:

AN:

4798

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10554

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67926

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.550

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hypertrophic cardiomyopathy

Uncertain:1

Dec 14, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 166 of the TNNI3 protein (p.Ser166Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TNNI3-related conditions. ClinVar contains an entry for this variant (Variation ID: 1357921). 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. This variant disrupts the p.Ser166 amino acid residue in TNNI3. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 12974739, 21533915, 22361390, 22675533). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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.

Cardiovascular phenotype

Uncertain:1

Jan 03, 2023

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.S166C variant (also known as c.497C>G), located in coding exon 7 of the TNNI3 gene, results from a C to G substitution at nucleotide position 497. The serine at codon 166 is replaced by cysteine, an amino acid with dissimilar properties. This amino acid position is not 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

Benign

0.14

CardioboostCm

Benign

0.033

BayesDel_addAF

Uncertain

0.088

BayesDel_noAF

Benign

-0.11

CADD

Uncertain

(source)

DANN

Uncertain

0.98

DEOGEN2

Pathogenic

0.89

D;D

Eigen

Benign

0.12

Eigen_PC

Benign

0.10

FATHMM_MKL

Uncertain

0.91

LIST_S2

Benign

0.57

T;T

M_CAP

Uncertain

0.10

MetaRNN

Benign

0.42

T;T

MetaSVM

Uncertain

0.34

MutationAssessor

Uncertain

2.0

M;.

PhyloP100

3.5

PrimateAI

Uncertain

0.56

PROVEAN

Uncertain

-2.4

N;.

REVEL

Uncertain

0.49

Sift

Benign

0.18

T;.

Sift4G

Benign

0.15

T;T

Vest4

0.27

ClinPred

0.81

GERP RS

3.7

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.43

Mutation Taster

=19/81

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over