rs749109513

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_001267550.2(TTN):c.55270-3T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,612,412 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

TTN
NM_001267550.2 splice_region, intron

Scores

Splicing: ADA: 0.0001929

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.335

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.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.5).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.55270-3T>C		splice_region_variant, intron_variant	Intron 284 of 362	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.55270-3T>C		splice_region_variant, intron_variant	Intron 284 of 362	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152036

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000404

AC:

AN:

247464

AF XY:

0.00000745

show subpopulations

Gnomad AFR exome

AF:

0.00

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:

0.00000894

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1460376

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

726448

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33414

American (AMR)

AF:

0.0000224

AC:

AN:

44628

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26092

East Asian (EAS)

AF:

0.00

AC:

AN:

39486

South Asian (SAS)

AF:

0.00

AC:

AN:

86160

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53324

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5754

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111220

Other (OTH)

AF:

0.00

AC:

AN:

60298

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152036

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74268

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41438

American (AMR)

AF:

0.00

AC:

AN:

15238

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5150

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67974

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

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:

0.00

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Oct 16, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

not provided

Uncertain:1

May 04, 2022

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.47566-3T>C variant in TTN has not been previously reported in individuals with cardiomyopathy but has been identified in 0.0008% (1/111878) of European chromosomes by gnomAD (http://gnomad.broadinstitute.org). This variant is located in the 3' splice region, but computational tools do not suggest an impact to splicing. However, this information is not predictive enough to rule out pathogenicity. In summary, while the clinical significance of the c.47566-3T>C variant is uncertain, these data suggest that it is more likely to be benign. ACMG/AMP Criteria applied: PM2_Supporting, BP4. -

Cardiovascular phenotype

Uncertain:1

Dec 27, 2019

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.28075-3T>C intronic variant results from a T to C substitution 3 nucleotides upstream from coding exon 112 in the TTN gene. This nucleotide position is not well conserved in available vertebrate species. Using the BDGP and ESEfinder splice site prediction tools, this alteration is not predicted to have any significant effect on this splice acceptor site; however, direct evidence is unavailable. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.50

CADD

Benign

9.0

(source)

DANN

Benign

0.76

PhyloP100

0.34

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.00019

dbscSNV1_RF

Benign

0.026

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

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

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over