2-178571529-ATTG-A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 1P and 5B. PM4_SupportingBP6BS2

The NM_001267550.2(TTN):c.74600_74602delCAA(p.Thr24867del) variant causes a disruptive inframe deletion change. The variant allele was found at a frequency of 0.00115 in 1,613,218 control chromosomes in the GnomAD database, including 2 homozygotes. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00093 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0012 ( 2 hom. )

Consequence

TTN
NM_001267550.2 disruptive_inframe_deletion

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:14

Conservation

PhyloP100: 5.00

Publications

2 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 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 was made for transcript

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

PM4

Nonframeshift variant in NON repetitive region in NM_001267550.2. Strenght limited to Supporting due to length of the change: 1aa.

BP6

Variant 2-178571529-ATTG-A is Benign according to our data. Variant chr2-178571529-ATTG-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 165840.

BS2

High Homozygotes in GnomAdExome4 at 2 AD,AR gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001267550.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTN	NM_001267550.2	MANE Select	c.74600_74602delCAA	p.Thr24867del	disruptive_inframe_deletion	Exon 326 of 363	NP_001254479.2
TTN	NM_001256850.1		c.69677_69679delCAA	p.Thr23226del	disruptive_inframe_deletion	Exon 276 of 313	NP_001243779.1
TTN	NM_133378.4		c.66896_66898delCAA	p.Thr22299del	disruptive_inframe_deletion	Exon 275 of 312	NP_596869.4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTN	ENST00000589042.5	TSL:5 MANE Select	c.74600_74602delCAA	p.Thr24867del	disruptive_inframe_deletion	Exon 326 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.74444_74446delCAA	p.Thr24815del	disruptive_inframe_deletion	Exon 324 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.74324_74326delCAA	p.Thr24775del	disruptive_inframe_deletion	Exon 324 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.000928

AC:

141

AN:

152016

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000656

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00104

Gnomad FIN

AF:

0.00264

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00150

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00112

AC:

278

AN:

247366

AF XY:

0.00113

show subpopulations

Gnomad AFR exome

AF:

0.0000647

Gnomad AMR exome

AF:

0.0000581

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00326

Gnomad NFE exome

AF:

0.00179

Gnomad OTH exome

AF:

0.000666

GnomAD4 exome

AF:

0.00117

AC:

1713

AN:

1461084

Hom.:

AF XY:

0.00120

AC XY:

870

AN XY:

726824

show subpopulations

African (AFR)

AF:

0.000179

AC:

AN:

33448

American (AMR)

AF:

0.0000895

AC:

AN:

44694

Ashkenazi Jewish (ASJ)

AF:

0.0000383

AC:

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39534

South Asian (SAS)

AF:

0.000232

AC:

AN:

86232

European-Finnish (FIN)

AF:

0.00268

AC:

143

AN:

53354

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

0.00134

AC:

1487

AN:

1111602

Other (OTH)

AF:

0.000862

AC:

AN:

60336

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.478

Heterozygous variant carriers

114

228

341

455

569

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

138

184

230

<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:

0.000927

AC:

141

AN:

152134

Hom.:

Cov.:

AF XY:

0.000968

AC XY:

AN XY:

74356

show subpopulations

African (AFR)

AF:

0.000120

AC:

AN:

41532

American (AMR)

AF:

0.0000655

AC:

AN:

15274

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5138

South Asian (SAS)

AF:

0.00104

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00264

AC:

AN:

10606

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00150

AC:

102

AN:

67968

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.493

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:

0.00113

Hom.:

Bravo

AF:

0.000608

EpiCase

AF:

0.00115

EpiControl

AF:

0.000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:14

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:6

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Jun 20, 2018

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Oct 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

TTN: PM4:Supporting, BS1

Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Genome Diagnostics Laboratory, University Medical Center Utrecht

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

not specified

Benign:4

Jan 28, 2024

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

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jul 22, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

p.Thr22299del in exon 275 of TTN: This variant is not expected to have clinical significance because it has been identified in 0.3% (21/6554) of Finnish chromos omes and 0.2% (132/66122) of European chromosomes by the Exome Aggregation Conso rtium (ExAC, http://exac.broadinstitute.org; dbSNP rs543318580).

Jun 16, 2017

Athena Diagnostics

Significance:Likely benign

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

Hypertrophic cardiomyopathy

Uncertain:1

Genetics and Genomics Program, Sidra Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:research

TTN-related disorder

Benign:1

Mar 16, 2021

PreventionGenetics, part of Exact Sciences

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).

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

Benign:1

Jan 27, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Cardiomyopathy

Benign:1

Nov 18, 2022

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Cardiovascular phenotype

Benign:1

Jul 05, 2019

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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 v4.9

Name

Calibrated prediction

Score

Prediction

PhyloP100

5.0

Mutation Taster

=56/44

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

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over