19-55154095-G-C

Variant names:

• chr19-55154095-G-C
• rs368861241
• NM_000363.5:c.484C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_000363.5(TNNI3):​c.484C>G​(p.Arg162Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,460,962 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R162L) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: TNNI3 NM_000363.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.73
• Publications: 27 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 20 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 chr19-55154094-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 626844.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.865

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000363.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TNNI3	NM_000363.5	MANE Select	c.484C>G	p.Arg162Gly	missense	Exon 7 of 8	NP_000354.4

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TNNI3	ENST00000344887.10	TSL:1 MANE Select	c.484C>G	p.Arg162Gly	missense	Exon 7 of 8	ENSP00000341838.5
	TNNI3	ENST00000665070.1		c.517C>G	p.Arg173Gly	missense	Exon 7 of 8	ENSP00000499482.1
	TNNI3	ENST00000714238.1		c.472C>G	p.Arg158Gly	missense	Exon 7 of 8	ENSP00000519518.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1460962 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726840

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44724

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: 86236

European-Finnish (FIN) AF: 0.0000190 AC: 1 AN: 52704

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5630

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1112000

Other (OTH) AF: 0.0000166 AC: 1 AN: 60360

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 1

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1

Jun 26, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with glycine at codon 162 of the TNNI3 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with TNNI3-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Different variants affecting the same codon (p.Arg162Trp, p.Arg162Gln and p.Arg162Pro), are considered to be disease-causing (ClinVar variation ID: 161396, 43389 and 43390), suggesting that glycine at this position is important for TNNI3 protein function. The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.18
CardioboostCm	Uncertain	0.34
BayesDel_addAF	Uncertain	0.081	D
BayesDel_noAF	Benign	-0.12
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D
Eigen	Benign	0.057
Eigen_PC	Benign	0.14
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Uncertain	0.94	D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.87	D
MetaSVM	Uncertain	0.16	D
MutationAssessor	Benign	1.4	L
PhyloP100		3.7
PrimateAI	Uncertain	0.60	T
PROVEAN	Uncertain	-4.0	D
REVEL	Uncertain	0.51
Sift	Uncertain	0.016	D
Sift4G	Pathogenic	0.0010	D
Polyphen		0.67	P
Vest4		0.53
MutPred		0.77		Gain of loop (P = 0.0045)
MVP		0.92
MPC		1.2
ClinPred		0.97	D
GERP RS		3.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.74
Mutation Taster		=18/82	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

Other links and lift over

dbSNP: rs368861241; hg19: chr19-55665463;