rs727505023

chr19-55156626-C-Achr19-55156626-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM5

The NM_000363.5(TNNI3):c.127G>T(p.Ala43Ser) variant causes a missense change. 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. A43T) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TNNI3 NM_000363.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 5.42

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 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_000363.5
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-55156626-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1333080.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNI3	NM_000363.5	c.127G>T	p.Ala43Ser	missense_variant	4/8	ENST00000344887.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TNNI3	ENST00000344887.10	c.127G>T	p.Ala43Ser	missense_variant	4/8	1	NM_000363.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1413592 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 698572

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

Apr 04, 2014

The Ala43Ser variant in TNNI3 has not been previously reported in individuals wi th cardiomyopathy and data from large population studies is insufficient to asse ss its frequency. Alanine (Ala) at position 43 is highly conserved in evolution; however, this variant was predicted to be benign using a computational tool cli nically validated by our laboratory. This tool's benign prediction is estimated to be correct 89% of the time (Jordan 2011). Additional information is needed to fully assess the clinical significance of the Ala43Ser variant. -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 29, 2023

The p.A43S variant (also known as c.127G>T), located in coding exon 4 of the TNNI3 gene, results from a G to T substitution at nucleotide position 127. The alanine at codon 43 is replaced by serine, an amino acid with similar properties. This amino acid position is highly 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	0.24
CardioboostCm	Benign	0.0073
BayesDel_addAF	Pathogenic	0.17	D
BayesDel_noAF	Uncertain	0.0
Cadd	Pathogenic	26
Dann	Uncertain	1.0
DEOGEN2	Benign	0.40	T;T;.
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.87	D;D;.
M_CAP	Uncertain	0.23	D
MetaRNN	Uncertain	0.48	T;T;T
MetaSVM	Uncertain	0.52	D
MutationAssessor	Benign	0.67	N;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-0.36	N;.;.
REVEL	Uncertain	0.39
Sift	Benign	0.47	T;.;.
Sift4G	Benign	0.64	T;T;.
Polyphen		1.0	D;.;.
Vest4		0.46
MutPred		0.30		Gain of phosphorylation at A43 (P = 0.0068);.;.;
MVP		0.95
MPC		0.78
ClinPred		0.91	D
GERP RS		5.0
Varity_R		0.60

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs727505023; hg19: chr19-55667994;