2-178799714-A-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_001267550.2(TTN):c.687T>G(p.Phe229Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000137 in 1,461,848 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/19 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. F229F) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 2.83

Publications

5 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 -1 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.27845544).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.687T>G	p.Phe229Leu	missense_variant	Exon 6 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7
TTN	NM_133379.5 link	c.687T>G	p.Phe229Leu	missense_variant	Exon 6 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.687T>G	p.Phe229Leu	missense_variant	Exon 6 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7
TTN	ENST00000360870.10 link	c.687T>G	p.Phe229Leu	missense_variant	Exon 6 of 46	5	NM_133379.5	ENSP00000354117.4		Q8WZ42-6

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000119

AC:

AN:

251100

AF XY:

0.00000737

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:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000137

AC:

AN:

1461848

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727234

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39686

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000171

AC:

AN:

1111990

Other (OTH)

AF:

0.0000166

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.470

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

Cov.:

Alfa

AF:

0.0000427

Hom.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.93

BayesDel_addAF

Uncertain

0.062

BayesDel_noAF

Benign

-0.090

CADD

Benign

(source)

DANN

Uncertain

0.99

Eigen

Benign

0.14

Eigen_PC

Benign

0.20

FATHMM_MKL

Uncertain

0.95

LIST_S2

Uncertain

0.86

D;D;D;.;D;D;D;D

M_CAP

Benign

0.032

MetaRNN

Benign

0.28

T;T;T;T;T;T;T;T

MetaSVM

Benign

-0.59

PhyloP100

2.8

PrimateAI

Uncertain

0.77

PROVEAN

Uncertain

-3.7

D;D;.;.;D;D;.;D

REVEL

Benign

0.25

Sift

Pathogenic

0.0

D;D;.;.;D;D;.;D

Sift4G

Uncertain

0.0090

.;.;.;.;.;.;.;D

Polyphen

0.78, 0.99

.;.;.;P;.;.;P;D

Vest4

0.49

MutPred

0.27

Loss of methylation at K224 (P = 0.0878);Loss of methylation at K224 (P = 0.0878);Loss of methylation at K224 (P = 0.0878);Loss of methylation at K224 (P = 0.0878);Loss of methylation at K224 (P = 0.0878);Loss of methylation at K224 (P = 0.0878);Loss of methylation at K224 (P = 0.0878);Loss of methylation at K224 (P = 0.0878);

MVP

0.30

MPC

0.15

ClinPred

0.87

GERP RS

4.9

Mutation Taster

=66/34

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

ClinVar

Computational scores

Splicing

Publications

Other links and lift over