19-55151917-C-T

Variant names:

• chr19-55151917-C-T
• rs397516356
• NM_000363.5:c.550G>A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP5

The NM_000363.5(TNNI3):​c.550G>A​(p.Glu184Lys) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E184Q) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TNNI3 NM_000363.5 missense, splice_region
• Scores: Splicing: ADA: 0.9519
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 1.03

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 5 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_000363.5
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-55151917-C-T is Pathogenic according to our data. Variant chr19-55151917-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 43394.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr19-55151917-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TNNI3	NM_000363.5	c.550G>A	p.Glu184Lys	missense_variant, splice_region_variant	Exon 8 of 8	ENST00000344887.10	NP_000354.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TNNI3	ENST00000344887.10	c.550G>A	p.Glu184Lys	missense_variant, splice_region_variant	Exon 8 of 8	1	NM_000363.5	ENSP00000341838.5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Primary dilated cardiomyopathy Pathogenic:1

Sep 06, 2013

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

proposed classification - variant undergoing re-assessment, contact laboratory -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.53
CardioboostCm	Uncertain	0.88
BayesDel_addAF	Uncertain	0.069	T
BayesDel_noAF	Benign	-0.14
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.70	D;T
Eigen	Benign	-0.27
Eigen_PC	Benign	-0.12
FATHMM_MKL	Uncertain	0.82	D
LIST_S2	Uncertain	0.87	D;D
M_CAP	Pathogenic	0.30	D
MetaRNN	Uncertain	0.52	D;D
MetaSVM	Uncertain	0.16	D
MutationAssessor	Benign	1.4	L;.
PrimateAI	Uncertain	0.71	T
PROVEAN	Benign	-2.3	N;.
REVEL	Benign	0.26
Sift	Benign	0.18	T;.
Sift4G	Benign	0.12	T;T
Polyphen		0.0010	B;.
Vest4		0.24
MutPred		0.26		Gain of MoRF binding (P = 0.0019);.;
MVP		0.85
MPC		0.88
ClinPred		0.85	D
GERP RS		4.5
Varity_R		0.59

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.95
dbscSNV1_RF	Pathogenic	0.73
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: rs397516356; hg19: chr19-55663285;