NM_001267550.2:c.70477A>T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):c.70477A>T(p.Thr23493Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000744 in 1,613,536 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. T23493T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 6.80

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 -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.112565845).

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.70477A>T	p.Thr23493Ser	missense	Exon 326 of 363	NP_001254479.2
TTN	NM_001256850.1		c.65554A>T	p.Thr21852Ser	missense	Exon 276 of 313	NP_001243779.1
TTN	NM_133378.4		c.62773A>T	p.Thr20925Ser	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.70477A>T	p.Thr23493Ser	missense	Exon 326 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.70321A>T	p.Thr23441Ser	missense	Exon 324 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.70201A>T	p.Thr23401Ser	missense	Exon 324 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152148

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000965

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

GnomAD4 exome

AF:

0.00000547

AC:

AN:

1461388

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726982

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33466

American (AMR)

AF:

0.00

AC:

AN:

44718

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26126

East Asian (EAS)

AF:

0.00

AC:

AN:

39650

South Asian (SAS)

AF:

0.00

AC:

AN:

86242

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53398

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

0.00000540

AC:

AN:

1111670

Other (OTH)

AF:

0.0000166

AC:

AN:

60358

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.537

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:

0.0000263

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74314

show subpopulations

African (AFR)

AF:

0.0000965

AC:

AN:

41442

American (AMR)

AF:

0.00

AC:

AN:

15274

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5172

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68008

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.538

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:

0.0000712

Hom.:

Bravo

AF:

0.0000264

ESP6500AA

AF:

0.000517

AC:

ESP6500EA

AF:

0.00

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Aug 04, 2016

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant classified as Uncertain Significance - Favor Benign. The p.Thr20925Ser v ariant in TTN has not been previously reported in individuals with cardiomyopath y but has been identified in 2/3870 African American chromosomes by the NHLBI Ex ome Sequencing Project (http://evs.gs.washington.edu/EVS/; dbSNP rs375675901). T hreonine (Thr) at position 20925 is not conserved in evolutionarily distant spec ies and >20 species carry a serine (Ser) at this position, raising the possibili ty that this change may be tolerated. Additional computational prediction tools do not provide strong support for or against an impact to the protein. In summar y, while the clinical significance of the p.Thr20925Ser variant is uncertain, th e presence of the variant amino acid in multiple other species suggest that it i s more likely to be benign.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.081

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.47

CADD

Benign

(source)

DANN

Benign

0.88

Eigen

Benign

-0.17

Eigen_PC

Benign

0.10

FATHMM_MKL

Uncertain

0.84

LIST_S2

Benign

0.65

M_CAP

Benign

0.0085

MetaRNN

Benign

0.11

MetaSVM

Benign

-1.0

MutationAssessor

Benign

-0.63

PhyloP100

6.8

PrimateAI

Uncertain

0.52

PROVEAN

Benign

-1.6

REVEL

Benign

0.093

Sift

Benign

0.81

Polyphen

0.0040

Vest4

0.15

MVP

0.099

MPC

0.077

ClinPred

0.36

GERP RS

5.7

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