2-178572285-C-T

Position:

chr2-178572285-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_001267550.2(TTN):c.73847G>A(p.Arg24616Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000329 in 1,612,452 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 2.66

Variant links:

Genes affected

TTN (HGNC:12403): (titin) This gene encodes a large abundant protein of striated muscle. The product of this gene is divided into two regions, a N-terminal I-band and a C-terminal A-band. The I-band, which is the elastic part of the molecule, contains two regions of tandem immunoglobulin domains on either side of a PEVK region that is rich in proline, glutamate, valine and lysine. The A-band, which is thought to act as a protein-ruler, contains a mixture of immunoglobulin and fibronectin repeats, and possesses kinase activity. An N-terminal Z-disc region and a C-terminal M-line region bind to the Z-line and M-line of the sarcomere, respectively, so that a single titin molecule spans half the length of a sarcomere. Titin also contains binding sites for muscle associated proteins so it serves as an adhesion template for the assembly of contractile machinery in muscle cells. It has also been identified as a structural protein for chromosomes. Alternative splicing of this gene results in multiple transcript variants. Considerable variability exists in the I-band, the M-line and the Z-disc regions of titin. Variability in the I-band region contributes to the differences in elasticity of different titin isoforms and, therefore, to the differences in elasticity of different muscle types. Mutations in this gene are associated with familial hypertrophic cardiomyopathy 9, and autoantibodies to titin are produced in patients with the autoimmune disease scleroderma. [provided by RefSeq, Feb 2012]

TTN links:

TTN-AS1 (HGNC:):

TTN-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TTN. . Gene score misZ -1.1021 (greater than the threshold 3.09). Trascript score misZ 6.9794 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, tibial muscular dystrophy, early-onset myopathy with fatal cardiomyopathy, autosomal recessive centronuclear myopathy, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 9, TTN-related myopathy, dilated cardiomyopathy 1G, arrhythmogenic right ventricular cardiomyopathy, myopathy, myofibrillar, 9, with early respiratory failure, familial isolated dilated cardiomyopathy, childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome, autosomal recessive limb-girdle muscular dystrophy type 2J.

BP4

Computational evidence support a benign effect (MetaRNN=0.09052917).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.73847G>A	p.Arg24616Gln	missense_variant	326/363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.73847G>A	p.Arg24616Gln	missense_variant	326/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.0000658

AC:

AN:

152046

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.000956

GnomAD3 exomes

AF:

0.0000928

AC:

AN:

247826

Hom.:

AF XY:

0.0000818

AC XY:

AN XY:

134398

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.000407

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000112

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000268

Gnomad OTH exome

AF:

0.000333

GnomAD4 exome

AF:

0.0000294

AC:

AN:

1460288

Hom.:

Cov.:

AF XY:

0.0000275

AC XY:

AN XY:

726256

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.000470

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000126

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152164

Hom.:

Cov.:

AF XY:

0.0000807

AC XY:

AN XY:

74370

show subpopulations

Gnomad4 AFR

AF:

0.000120

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.000946

Alfa

AF:

0.0000567

Hom.:

Bravo

AF:

0.000178

ExAC

AF:

0.0000745

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2Benign:1

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Mar 20, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Nov 17, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Nov 02, 2022	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 03, 2017

- -

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 08, 2017

Lines of evidence used in support of classification: UNCERTAIN: Alteration(s) of Uncertain Clinical Significance Detected -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 31, 2016

The p.R15551Q variant (also known as c.46652G>A), located in coding exon 153 of the TTN gene, results from a G to A substitution at nucleotide position 46652. This alteration is located in the A-band region of the N2-B isoform of the titin protein. The arginine at codon 15551 is replaced by glutamine, an amino acid with highly similar properties. This variant was previously reported in the SNPDatabase as rs201694149. Based on data from ExAC, the A allele has an overall frequency of less than 0.01% (9/104998). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. 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

0.11

BayesDel_addAF

Benign

-0.34

BayesDel_noAF

Benign

-0.40

CADD

Benign

DANN

Benign

0.93

Eigen

Uncertain

0.47

Eigen_PC

Uncertain

0.55

FATHMM_MKL

Uncertain

0.88

LIST_S2

Pathogenic

0.98

D;D;D;.;D;D;D

M_CAP

Benign

0.050

MetaRNN

Benign

0.091

T;T;T;T;T;T;T

MetaSVM

Benign

-0.73

MutationAssessor

Benign

1.5

.;.;.;L;.;.;L

PrimateAI

Uncertain

0.53

PROVEAN

Uncertain

-2.4

N;N;.;.;N;N;.

REVEL

Benign

0.26

Sift

Benign

0.24

T;T;.;.;T;T;.

Polyphen

1.0

.;.;.;D;.;.;D

Vest4

0.42

MVP

0.20

MPC

0.24

ClinPred

0.093

GERP RS

6.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over