rs786205288

chr19-55156250-G-Achr19-55156250-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM1 BP4

The NM_000363.5(TNNI3):c.233C>T(p.Thr78Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000685 in 1,460,100 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict 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. T78S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: TNNI3 NM_000363.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.418

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 1 ACMG points.

• PM1: In a chain Troponin I, cardiac muscle (size 208) in uniprot entity TNNI3_HUMAN there are 152 pathogenic changes around while only 19 benign (89%) in NM_000363.5
• BP4: Computational evidence support a benign effect (MetaRNN=0.28996202).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNI3	NM_000363.5	c.233C>T	p.Thr78Ile	missense_variant	5/8	ENST00000344887.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TNNI3	ENST00000344887.10	c.233C>T	p.Thr78Ile	missense_variant	5/8	1	NM_000363.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000831 AC: 2 AN: 240612 Hom.: 0 AF XY: 0.00000755 AC XY: 1 AN XY: 132490

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 SAS exome AF: 0.0000659

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000685 AC: 10 AN: 1460100 Hom.: 0 Cov.: 32 AF XY: 0.00000826 AC XY: 6 AN XY: 726426

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000928

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000468 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Nov 09, 2015

The p.Thr78Ile variant in TNNI3 has not been previously reported in individuals with cardiomyopathy. Data from large population studies is insufficient to asses s the frequency of this variant. Computational prediction tools and conservation analysis do not provide strong support for or against an impact to the protein. In summary, the clinical significance of the p.Thr78Ile variant is uncertain. -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Mar 28, 2023

This missense variant replaces threonine with isoleucine at codon 78 of the TNNI3 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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 been identified in 2/240612 chromosomes in the general population by the Genome Aggregation Database (gnomAD). 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 v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
CardioboostCm	Benign	0.038
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.22
Cadd	Benign	21
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D;D
Eigen	Benign	-0.31
Eigen_PC	Benign	-0.23
FATHMM_MKL	Benign	0.20	N
LIST_S2	Benign	0.85	D;D
M_CAP	Uncertain	0.22	D
MetaRNN	Benign	0.29	T;T
MetaSVM	Uncertain	0.028	D
MutationAssessor	Benign	0.0	N;.
MutationTaster	Benign	0.99	D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-1.9	N;.
REVEL	Benign	0.25
Sift	Uncertain	0.0030	D;.
Sift4G	Uncertain	0.0020	D;D
Polyphen		0.40	B;.
Vest4		0.32
MutPred		0.41		Gain of catalytic residue at L83 (P = 0.0224);.;
MVP		0.89
MPC		0.78
ClinPred		0.33	T
GERP RS		3.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.65

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: rs786205288; hg19: chr19-55667618;