chr2-178560129-A-G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):c.86003T>C(p.Ile28668Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000378 in 1,613,582 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I28668V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:2

Conservation

PhyloP100: 7.45

Publications

0 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 -3 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.25410354).

BP6

Variant 2-178560129-A-G is Benign according to our data. Variant chr2-178560129-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 178179.

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.86003T>C	p.Ile28668Thr	missense	Exon 326 of 363	NP_001254479.2
TTN	NM_001256850.1		c.81080T>C	p.Ile27027Thr	missense	Exon 276 of 313	NP_001243779.1
TTN	NM_133378.4		c.78299T>C	p.Ile26100Thr	missense	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.86003T>C	p.Ile28668Thr	missense	Exon 326 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.85847T>C	p.Ile28616Thr	missense	Exon 324 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.85727T>C	p.Ile28576Thr	missense	Exon 324 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.000118

AC:

AN:

152116

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000434

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000484

AC:

AN:

247972

AF XY:

0.0000446

show subpopulations

Gnomad AFR exome

AF:

0.000711

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000893

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000294

AC:

AN:

1461466

Hom.:

Cov.:

AF XY:

0.0000261

AC XY:

AN XY:

726998

show subpopulations

African (AFR)

AF:

0.000687

AC:

AN:

33468

American (AMR)

AF:

0.00

AC:

AN:

44718

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26128

East Asian (EAS)

AF:

0.00

AC:

AN:

39668

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86252

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53378

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5762

European-Non Finnish (NFE)

AF:

0.0000153

AC:

AN:

1111728

Other (OTH)

AF:

0.0000331

AC:

AN:

60364

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.506

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

AF:

0.000118

AC:

AN:

152116

Hom.:

Cov.:

AF XY:

0.000108

AC XY:

AN XY:

74288

show subpopulations

African (AFR)

AF:

0.000434

AC:

AN:

41444

American (AMR)

AF:

0.00

AC:

AN:

15264

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5174

South Asian (SAS)

AF:

0.00

AC:

AN:

4808

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68024

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

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:

0.000164

Hom.:

Bravo

AF:

0.000144

ESP6500AA

AF:

0.000266

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000497

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:2

Oct 10, 2013

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The Ile26100Thr variant in TTN has not been reported in individuals with cardiom yopathy but has been identified in 1/3766 African American chromosomes by the NH LBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/). Computational analyses (biochemical amino acid properties, conservation, AlignGVGD, and SIFT) do not provide strong support for or against an impact to the protein. Additiona l information is needed to fully assess the clinical significance of the Ile2610 0Thr variant.

Mar 17, 2025

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Uncertain:1Benign:1

May 23, 2018

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Oct 02, 2020

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

Uncertain:1

Dec 05, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Cardiomyopathy

Uncertain:1

Oct 30, 2017

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

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Cardiovascular phenotype

Benign:1

Mar 03, 2020

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

AlphaMissense

Pathogenic

0.71

BayesDel_addAF

Benign

-0.24

BayesDel_noAF

Benign

-0.20

CADD

Benign

(source)

DANN

Benign

0.52

Eigen

Uncertain

0.56

Eigen_PC

Uncertain

0.52

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.87

M_CAP

Benign

0.042

MetaRNN

Benign

0.25

MetaSVM

Uncertain

-0.28

MutationAssessor

Uncertain

2.8

PhyloP100

7.4

PrimateAI

Uncertain

0.55

PROVEAN

Uncertain

-3.4

REVEL

Uncertain

0.42

Sift

Uncertain

0.013

Polyphen

0.92

Vest4

0.33

MVP

0.68

MPC

0.31

ClinPred

0.16

GERP RS

5.9

Mutation Taster

=88/12

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

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