chr19-55154035-C-T

Position:

• chr19-55154035-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PP5_Very_Strong

The NM_000363.5(TNNI3):​c.544G>A​(p.Glu182Lys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. E182E) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TNNI3 NM_000363.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 6.06

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 Pathogenic. Variant got 12 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, 16 uncertain in NM_000363.5
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-55154035-C-T is Pathogenic according to our data. Variant chr19-55154035-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 43392.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-55154035-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNI3	NM_000363.5	c.544G>A	p.Glu182Lys	missense_variant	7/8	ENST00000344887.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TNNI3	ENST00000344887.10	c.544G>A	p.Glu182Lys	missense_variant	7/8	1	NM_000363.5	P1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1459692 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 726196

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.: 30

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Primary dilated cardiomyopathy Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Sep 10, 2014	The Glu182Lys variant in TNNI3 has been identified by our laboratory as de novo in 1 African American neonate with DCM and 1 Caucasian infant with DCM. In addit ion, it has not been identified in large population studies. Computational predi ction tools and conservation analysis do not provide strong support for or again st an impact to the protein. In summary, this variant meets our criteria to be c lassified as pathogenic (http://www.partners.org/personalizedmedicine/LMM) based upon de novo occurrence in multiple cases. -
Likely pathogenic, no assertion criteria provided	clinical testing	Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital	Oct 12, 2015	- -

Cardiomyopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Dec 12, 2018

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Oct 25, 2012

The Glu182Lys mutation in the TNNI3 gene has been reported in association with cardiomyopathy (Lakdawala N et al., 2012). Lakdawla et al. reported Glu182Lys occurred de novo in one patient with DCM and it was absent from approximately 400 control samples. Also, the NHLBI ESP Exome Variant Server reports Glu182Lys was not observed in approximately 6,000 samples from individuals of European and African American backgrounds, indicating it is not a common benign variant in these populations. Glu182Lys results in a non-conservative amino acid substitution of a negatively charged Glutamic acid with a positively charged Lysine at a position that is highly conserved across species. Furthermore, mutations in nearby codons (Lys183Asn, Lys183Glu, Asn185Lys, Arg186Gln) have been reported in association with cardiomyopathy, supporting the functional importance of this region of the protein. In summary, Glu182Lys in the TNNI3 gene is interpreted as a disease-causing mutation. The variant is found in DCM panel(s). -

Hypertrophic cardiomyopathy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 05, 2022

This variant is not present in population databases (gnomAD no frequency). For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15"). ClinVar contains an entry for this variant (Variation ID: 43392). This missense change has been observed in individual(s) with dilated cardiomyopathy (PMID: 22464770, 24503780, 27532257, 32458740). In at least one individual the variant was observed to be de novo. This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 182 of the TNNI3 protein (p.Glu182Lys). -

Dilated cardiomyopathy 1FF Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Institute of Human Genetics Munich, Klinikum Rechts Der Isar, TU München

Aug 02, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.44
CardioboostCm	Uncertain	0.43
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.030
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.49	T;T
Eigen	Benign	-0.054
Eigen_PC	Benign	0.12
FATHMM_MKL	Uncertain	0.91	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Uncertain	0.088	D
MetaRNN	Uncertain	0.59	D;D
MetaSVM	Uncertain	0.22	D
MutationAssessor	Benign	0.58	N;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-0.90	N;.
REVEL	Uncertain	0.32
Sift	Benign	0.36	T;.
Sift4G	Benign	0.41	T;T
Polyphen		0.088	B;.
Vest4		0.79
MutPred		0.49		Gain of MoRF binding (P = 7e-04);.;
MVP		0.97
MPC		0.87
ClinPred		0.85	D
GERP RS		4.7
Varity_R		0.37

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs397516355; hg19: chr19-55665403;