2-178790766-G-A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001267550.2(TTN):c.1742C>T(p.Pro581Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000208 in 1,614,068 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/19 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. P581P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00022 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:10B:2

Conservation

PhyloP100: 0.685

Publications

6 publications found

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 Gene-Disease associations (from GenCC):

dilated cardiomyopathy
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
dilated cardiomyopathy 1G
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
early-onset myopathy with fatal cardiomyopathy
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P
TTN-related myopathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
myopathy, myofibrillar, 9, with early respiratory failure
Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, ClinGen, Ambry Genetics
tibial muscular dystrophy
Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
autosomal recessive limb-girdle muscular dystrophy type 2J
Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
hypertrophic cardiomyopathy 9
Inheritance: AD Classification: MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia
familial isolated dilated cardiomyopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
autosomal recessive centronuclear myopathy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
arrhythmogenic right ventricular cardiomyopathy
Inheritance: AD Classification: LIMITED Submitted by: ClinGen
congenital myopathy
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
hereditary skeletal muscle disorder
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
hypertrophic cardiomyopathy
Inheritance: AD Classification: LIMITED Submitted by: ClinGen

TTN links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.038096786).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.1742C>T	p.Pro581Leu	missense_variant	Exon 11 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7
TTN	NM_133379.5 link	c.1742C>T	p.Pro581Leu	missense_variant	Exon 11 of 46	ENST00000360870.10	NP_596870.2	Q8WZ42-6Q7Z3B7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.1742C>T	p.Pro581Leu	missense_variant	Exon 11 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7
TTN	ENST00000360870.10 link	c.1742C>T	p.Pro581Leu	missense_variant	Exon 11 of 46	5	NM_133379.5	ENSP00000354117.4		Q8WZ42-6

Frequencies

GnomAD3 genomes

AF:

0.000112

AC:

AN:

152132

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000197

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:

0.000132

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000796

AC:

AN:

251380

AF XY:

0.000103

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.000198

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000158

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000218

AC:

318

AN:

1461818

Hom.:

Cov.:

AF XY:

0.000210

AC XY:

153

AN XY:

727218

show subpopulations

African (AFR)

AF:

0.0000597

AC:

AN:

33476

American (AMR)

AF:

0.0000447

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.0000765

AC:

AN:

26134

East Asian (EAS)

AF:

0.000554

AC:

AN:

39686

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000252

AC:

280

AN:

1111974

Other (OTH)

AF:

0.000116

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.468

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

100

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000112

AC:

AN:

152250

Hom.:

Cov.:

AF XY:

0.0000940

AC XY:

AN XY:

74436

show subpopulations

African (AFR)

AF:

0.000120

AC:

AN:

41540

American (AMR)

AF:

0.000196

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10610

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000132

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.516

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000161

Hom.:

Bravo

AF:

0.000125

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000988

AC:

EpiCase

AF:

0.000273

EpiControl

AF:

0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:10Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Dec 30, 2016

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Dec 01, 2023

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

TTN: PM2, BP4 -

Jan 16, 2024

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not specified

Uncertain:1Benign:2

Jul 21, 2017

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

p.Pro581Leu in exon 11 of TTN: This variant is not expected to have clinical sig nificance due to a lack of conservation across species, including mammals. Of no te, multiple mammals have a leucine (Leu) at this position despite high nearby a mino acid conservation. In addition, computational prediction tools do not sugge st a high likelihood of impact to the protein. This variant has also been identi fied in 20/126608 of European chromosomes by the Genome Aggregation Database (gn omAD, http://gnomad.broadinstitute.org; dbSNP rs199778910). -

Jul 18, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 09, 2025

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

BS1;BP1 -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Uncertain:1

Jan 15, 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. -

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

Uncertain:1

Nov 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 15, 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 15, 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

Uncertain:1

Jan 15, 2018

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Tibial muscular dystrophy

Uncertain:1

Jan 15, 2018

Illumina Laboratory Services, Illumina

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.054

BayesDel_addAF

Benign

-0.44

BayesDel_noAF

Benign

-0.62

CADD

Benign

(source)

DANN

Benign

0.63

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.0

FATHMM_MKL

Benign

0.0028

LIST_S2

Benign

0.58

T;T;.;T;T

M_CAP

Benign

0.011

MetaRNN

Benign

0.038

T;T;T;T;T

MetaSVM

Benign

-1.0

PhyloP100

0.69

PrimateAI

Benign

0.21

PROVEAN

Benign

-0.17

N;.;.;.;N

REVEL

Benign

0.033

Sift

Benign

0.52

T;.;.;.;T

Sift4G

Benign

0.48

.;.;.;.;T

Polyphen

0.0

.;.;B;B;B

Vest4

0.079

MVP

0.13

MPC

0.085

ClinPred

0.023

GERP RS

2.5

Mutation Taster

=82/18

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over