rs397516350

Positions:

• chr19-55154117-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000363.5(TNNI3):​c.462G>A​(p.Met154Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: TNNI3 NM_000363.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.62

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in NM_000363.5
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNI3	NM_000363.5	c.462G>A	p.Met154Ile	missense_variant	7/8	ENST00000344887.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TNNI3	ENST00000344887.10	c.462G>A	p.Met154Ile	missense_variant	7/8	1	NM_000363.5	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Sep 19, 2012

Variant classified as Uncertain Significance - Favor Benign. The Met154Ile varia nt in TNNI3 has not been reported in the literature nor previously identified by our laboratory. Computational analyses (biochemical amino acid properties, cons ervation, AlignGVGD, PolyPhen2, and SIFT) suggest that this variant may not impa ct the protein and 2 fish species carry this variant, suggesting that the change to isoleucine (Ile) may be tolerated. In summary, this variant is less liekly d isease causing but additional studies are needed to fully assess its clinical si gnificance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.070
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;D
Eigen	Benign	0.084
Eigen_PC	Benign	0.19
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.49	T;T
MetaSVM	Uncertain	0.48	D
MutationAssessor	Uncertain	2.1	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.72	T
PROVEAN	Uncertain	-3.6	D;.
REVEL	Uncertain	0.57
Sift	Benign	0.034	D;.
Sift4G	Uncertain	0.053	T;T
Polyphen		0.060	B;.
Vest4		0.32
MutPred		0.73		Loss of catalytic residue at M154 (P = 0.0057);.;
MVP		0.90
MPC		1.7
ClinPred		0.98	D
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.86

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

Other links and lift over

dbSNP: rs397516350; hg19: chr19-55665485;