rs141687561

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 0P and 7B. BP4_ModerateBP6BS1

The NM_001267550.2(TTN):c.17183-9T>C variant causes a splice polypyrimidine tract, intron change. The variant allele was found at a frequency of 0.00278 in 1,585,410 control chromosomes in the GnomAD database, including 15 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0014 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0029 ( 15 hom. )

Consequence

TTN
NM_001267550.2 splice_polypyrimidine_tract, intron

Scores

Splicing: ADA: 0.1878

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:13

Conservation

PhyloP100: 4.37

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 Benign. Variant got -7 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.31).

BP6

Variant 2-178731592-A-G is Benign according to our data. Variant chr2-178731592-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46623.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Benign=5, Uncertain_significance=3}. Variant chr2-178731592-A-G is described in Lovd as [Benign]. Variant chr2-178731592-A-G is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population nfe. gnomad4_exome allele frequency = 0.00292 (4185/1433136) while in subpopulation NFE AF= 0.00361 (3966/1097876). AF 95% confidence interval is 0.00352. There are 15 homozygotes in gnomad4_exome. There are 1936 alleles in male gnomad4_exome subpopulation. Median coverage is 36. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.17183-9T>C		splice_polypyrimidine_tract_variant, intron_variant		ENST00000589042.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.17183-9T>C		splice_polypyrimidine_tract_variant, intron_variant		5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.503-2912A>G		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.00141

AC:

215

AN:

152156

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000676

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000786

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00253

Gnomad OTH

AF:

0.000957

GnomAD3 exomes

AF:

0.00133

AC:

300

AN:

225412

Hom.:

AF XY:

0.00127

AC XY:

155

AN XY:

121766

show subpopulations

Gnomad AFR exome

AF:

0.000462

Gnomad AMR exome

AF:

0.000946

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000251

Gnomad NFE exome

AF:

0.00242

Gnomad OTH exome

AF:

0.00112

GnomAD4 exome

AF:

0.00292

AC:

4185

AN:

1433136

Hom.:

Cov.:

AF XY:

0.00273

AC XY:

1936

AN XY:

709882

show subpopulations

Gnomad4 AFR exome

AF:

0.000372

Gnomad4 AMR exome

AF:

0.000806

Gnomad4 ASJ exome

AF:

0.0000412

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000245

Gnomad4 FIN exome

AF:

0.000344

Gnomad4 NFE exome

AF:

0.00361

Gnomad4 OTH exome

AF:

0.00258

GnomAD4 genome

AF:

0.00141

AC:

215

AN:

152274

Hom.:

Cov.:

AF XY:

0.00133

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.000674

Gnomad4 AMR

AF:

0.000785

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000941

Gnomad4 NFE

AF:

0.00253

Gnomad4 OTH

AF:

0.000947

Alfa

AF:

0.00148

Hom.:

Bravo

AF:

0.00146

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:13

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Benign:8

Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 31, 2020	Variant summary: TTN c.13451-9T>C alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational 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 0.0013 in 225412 control chromosomes. The observed variant frequency is approximately 3.4-fold the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is benign. c.13451-9T>C has been reported in the literature in individuals affected with Dilated Cardiomyopathy (example-Pugh_2014). This report does not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, citing the variant as benign/likely benign (n=4) and uncertain significance (n=1). Based on the evidence outlined above, the variant was classified as benign. -
Likely benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Nov 15, 2016	c.13451-9T>C in intron 55 of TTN: This variant is not expected to have clinical significance because a T>C change at this position does not diverge from the spl ice consensus sequence and is therefore unlikely to impact splicing. In addition , this variant has been identified in 0.2% (144/64702) of European chromosomes b y the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs141687561). -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Apr 09, 2014	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. -
Likely benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Aug 07, 2015	- -
Benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

not provided

Benign: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	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -

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. -

Dilated cardiomyopathy 1G

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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

Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 31, 2024

- -

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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.31

Cadd

Benign

Dann

Benign

0.77

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.19

dbscSNV1_RF

Benign

0.46

SpliceAI score (max)

0.020

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