chr2-178543065-A-G

Position:

chr2-178543065-A-G

Variant summary

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

The NM_001267550.2(TTN):c.96904+4T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000135 in 1,548,308 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

TTN
NM_001267550.2 splice_region, intron

Scores

Splicing: ADA: 0.00006381

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:10B:6

Conservation

PhyloP100: -0.402

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 -5 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.54).

BP6

Variant 2-178543065-A-G is Benign according to our data. Variant chr2-178543065-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 47572.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=8, Benign=3}. Variant chr2-178543065-A-G is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.96904+4T>C		splice_region_variant, intron_variant		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.96904+4T>C		splice_region_variant, intron_variant		5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000140

AC:

AN:

149918

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000739

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000531

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:

0.000973

GnomAD3 exomes

AF:

0.000172

AC:

AN:

203186

Hom.:

AF XY:

0.000164

AC XY:

AN XY:

109670

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000427

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000124

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000205

Gnomad OTH exome

AF:

0.000423

GnomAD4 exome

AF:

0.000134

AC:

188

AN:

1398276

Hom.:

Cov.:

AF XY:

0.000112

AC XY:

AN XY:

689842

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000608

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000511

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000147

Gnomad4 OTH exome

AF:

0.000104

GnomAD4 genome

AF:

0.000140

AC:

AN:

150032

Hom.:

Cov.:

AF XY:

0.000192

AC XY:

AN XY:

73088

show subpopulations

Gnomad4 AFR

AF:

0.0000737

Gnomad4 AMR

AF:

0.000530

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:

0.000962

Alfa

AF:

0.000285

Hom.:

Bravo

AF:

0.000174

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:10Benign:6

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2Benign:2

Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Likely benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Nov 13, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Apr 21, 2022	- -

not specified

Uncertain:2Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Feb 06, 2015	The c.89200+4T>C variant in TTN has been identified by our laboratory in 1 adult with HCM and has also been identified in 6/11510 Latino chromosomes and 10/6542 6 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.br oadinstitute.org; dbSNP rs373514079). This variant is located in the 5' splice r egion and computational tools do not suggest an impact to splicing. However, thi s information is not predictive enough to rule out pathogenicity. In summary, th e clinical significance of the c.89200+4T>C variant is uncertain. -
Benign, criteria provided, single submitter	clinical testing	GeneDx	May 21, 2015	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Feb 05, 2024	Variant summary: TTN c.89200+4T>C alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00017 in 203186 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in TTN causing Cardiomyopathy (0.00017 vs 0.00063), allowing no conclusion about variant significance. c.89200+4T>C has been reported in the literature as a VUS in a setting of multigene panel testing in an individual affected with Hypertrophic Cardiomyopathy (Mademont-Soler_2017). This report does not provide unequivocal conclusions about association of the variant with Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 28771489). ClinVar contains an entry for this variant (Variation ID: 47572). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Dilated cardiomyopathy 1G

Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Knight Diagnostic Laboratories, Oregon Health and Sciences University	Apr 19, 2016	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	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. -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

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

Sep 07, 2017

- -

Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

Hypertrophic cardiomyopathy 9

Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Knight Diagnostic Laboratories, Oregon Health and Sciences University

Apr 19, 2016

- -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 18, 2019

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.54

CADD

Benign

DANN

Benign

0.62

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.000064

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