chr2-178735913-C-T

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001267550.2(TTN):c.14533G>A(p.Asp4845Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000111 in 1,613,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. D4845D) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00017 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00010 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:4

Conservation

PhyloP100: -0.0580

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:44124): (TTN antisense RNA 1) This gene encodes a non-coding RNA transcribed from the opposite strand to the titin gene. [provided by RefSeq, Aug 2016]

TTN-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -5 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.044059485).

BP6

Variant 2-178735913-C-T is Benign according to our data. Variant chr2-178735913-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46588.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Benign=1, Uncertain_significance=7}. Variant chr2-178735913-C-T is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.14533G>A	p.Asp4845Asn	missense_variant	Exon 50 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.14533G>A	p.Asp4845Asn	missense_variant	Exon 50 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000164

AC:

AN:

152164

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000338

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.000118

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000141

AC:

AN:

248926

Hom.:

AF XY:

0.000126

AC XY:

AN XY:

135032

show subpopulations

Gnomad AFR exome

AF:

0.000323

Gnomad AMR exome

AF:

0.0000869

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000557

Gnomad SAS exome

AF:

0.000359

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000124

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.000105

AC:

153

AN:

1461600

Hom.:

Cov.:

AF XY:

0.000105

AC XY:

AN XY:

727084

show subpopulations

Gnomad4 AFR exome

AF:

0.000239

Gnomad4 AMR exome

AF:

0.0000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000756

Gnomad4 SAS exome

AF:

0.000406

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000756

Gnomad4 OTH exome

AF:

0.000282

GnomAD4 genome

AF:

0.000171

AC:

AN:

152282

Hom.:

Cov.:

AF XY:

0.000161

AC XY:

AN XY:

74452

show subpopulations

Gnomad4 AFR

AF:

0.000337

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000118

Gnomad4 OTH

AF:

0.000947

Alfa

AF:

0.000195

Hom.:

Bravo

AF:

0.000204

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.000258

AC:

ESP6500EA

AF:

0.000121

AC:

ExAC

AF:

0.000149

AC:

Asia WGS

AF:

0.000867

AC:

AN:

3476

EpiCase

AF:

0.000109

EpiControl

AF:

0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8Benign:4

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2Benign:1

Oct 28, 2020

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 03, 2023

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 05, 2018

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Uncertain:1Benign:1

Jun 17, 2013

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant classified as Uncertain Significance - Favor Benign. The Asp3601Asn vari ant in TTN has been identified by our laboratory in 3 individuals with DCM (1 So uth Asian infant, 1 Caucasian child, and 1 Caucasian adult; LMM unpublished data ). This variant has also been identified in 1/8284 European American chromosomes and 1/3870 African American chromosomes by the NHLBI Exome Sequencing Project ( http://evs.gs.washington.edu/EVS). Aspartic acid (Asp) at position 3601 is not c onserved in evolutionarily distant species, including within mammals, suggesting that a change at this position may be tolerated. Other computational analyses ( biochemical amino acid properties, AlignGVGD, PolyPhen2, and SIFT) also suggest that this variant may not impact the protein, though this information is not pre dictive enough to rule out pathogenicity. The lack of conservation suggests that this variant is more likely benign, but additional studies are needed to fully assess its clinical significance. -

Mar 08, 2024

Athena Diagnostics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

TTN-related disorder

Uncertain:1

Mar 26, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The TTN c.14533G>A variant is predicted to result in the amino acid substitution p.Asp4845Asn. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.036% of alleles in individuals of South Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

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

Uncertain:1

Jun 14, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dilated cardiomyopathy 1G

Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Tibial muscular dystrophy

Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.070

BayesDel_addAF

Benign

-0.43

BayesDel_noAF

Benign

-0.55

CADD

Benign

8.0

DANN

Benign

0.59

Eigen

Benign

-0.86

Eigen_PC

Benign

-0.78

FATHMM_MKL

Benign

0.094

LIST_S2

Benign

0.73

T;T;.;T

M_CAP

Benign

0.021

MetaRNN

Benign

0.044

T;T;T;T

MetaSVM

Benign

-0.95

PrimateAI

Benign

0.27

PROVEAN

Benign

-1.9

N;.;.;.

REVEL

Benign

0.10

Sift

Benign

0.47

T;.;.;.

Polyphen

0.038

.;.;B;B

Vest4

0.23

MVP

0.14

MPC

0.087

ClinPred

0.0043

GERP RS

3.0

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