2-178577990-A-G

Position:

chr2-178577990-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP2BP4

The NM_001267550.2(TTN):c.68525T>C(p.Ile22842Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,611,456 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Splicing: ADA: 0.001314

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 9.27

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 Uncertain_significance. Variant got 0 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=0.39458025).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.68525T>C	p.Ile22842Thr	missense_variant	322/363	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.68525T>C	p.Ile22842Thr	missense_variant	322/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152100

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000122

AC:

AN:

246486

Hom.:

AF XY:

0.0000150

AC XY:

AN XY:

133642

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000294

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000179

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000171

AC:

AN:

1459356

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

725770

show subpopulations

Gnomad4 AFR exome

AF:

0.0000600

Gnomad4 AMR exome

AF:

0.0000226

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000253

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000153

Gnomad4 OTH exome

AF:

0.0000332

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152100

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74272

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000142

Hom.:

Bravo

AF:

0.0000264

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000122

AC:

ExAC

AF:

0.0000166

AC:

EpiCase

AF:

0.0000546

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jun 20, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Nov 01, 2013	The Ile21201Thr variant in the TTN gene has not been reported as a disease-causing mutation or as a benign polymorphism, to our knowledge. Ile21201Thr results in a non-conservative amino acid substitution of a non-polar Isoleucine with a polar Threonine at a position that is conserved across species. In silico analysis predicts Ile21201Thr is damaging to the protein structure/function. Furthermore, the Ile21201Thr variant was not observed with any significant frequency in approximately 6,000 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating that is is not a common benign variant in these populations. Ile21201Thr is located in the A-band region of titin. The majority of mutations in the TTN gene are truncating mutations and these are located in the A-band region of titin (Herman D et al., 2012). The variant is found in TTN panel(s). -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Feb 17, 2023	- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jun 30, 2012

The Ile20274Thr variant in TTN has not been reported in the literature nor previ ously identified by our laboratory. This variant has been identified in 1/8218 E uropean American chromosomes from a broad population screened by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/). Computational analyses (biochemical amino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT ) suggest that the Ile20274Thr variant may impact the protein, though this infor mation is not predictive enough to determine pathogenicity. This variant affect s the third to last base of the exon, which is part of the splice consensus sequ ence but splice prediction tools do not predict an impact (their accuracy is unk nown). Additional information is needed to fully assess the clinical significanc e of the Ile20274Thr variant. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.51

BayesDel_addAF

Benign

-0.038

BayesDel_noAF

Benign

-0.21

CADD

Benign

DANN

Benign

0.84

Eigen

Pathogenic

0.78

Eigen_PC

Pathogenic

0.75

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.94

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

M_CAP

Benign

0.048

MetaRNN

Benign

0.39

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

MetaSVM

Uncertain

-0.14

MutationAssessor

Benign

1.6

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

PrimateAI

Uncertain

0.76

PROVEAN

Uncertain

-3.3

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

REVEL

Uncertain

0.51

Sift

Uncertain

0.0090

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

Polyphen

1.0

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

Vest4

0.56

MVP

0.55

MPC

0.52

ClinPred

0.21

GERP RS

5.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.0013

dbscSNV1_RF

Benign

0.016

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