chr2-178590029-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4BP6

The NM_001267550.2(TTN):c.61696G>A(p.Val20566Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000694 in 1,613,020 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). Synonymous variant affecting the same amino acid position (i.e. V20566V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000072 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8B:3

Conservation

PhyloP100: 7.86

Publications

4 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=0.31257135).

BP6

Variant 2-178590029-C-T is Benign according to our data. Variant chr2-178590029-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 283714.

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.61696G>A	p.Val20566Ile	missense	Exon 304 of 363	NP_001254479.2
TTN	NM_001256850.1		c.56773G>A	p.Val18925Ile	missense	Exon 254 of 313	NP_001243779.1
TTN	NM_133378.4		c.53992G>A	p.Val17998Ile	missense	Exon 253 of 312	NP_596869.4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTN	ENST00000589042.5	TSL:5 MANE Select	c.61696G>A	p.Val20566Ile	missense	Exon 304 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.61540G>A	p.Val20514Ile	missense	Exon 302 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.61420G>A	p.Val20474Ile	missense	Exon 302 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152056

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.0000441

Gnomad OTH

AF:

0.000479

GnomAD2 exomes

AF:

0.0000767

AC:

AN:

247880

AF XY:

0.0000744

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.000233

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000803

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000719

AC:

105

AN:

1460964

Hom.:

Cov.:

AF XY:

0.0000688

AC XY:

AN XY:

726756

show subpopulations

African (AFR)

AF:

0.0000897

AC:

AN:

33436

American (AMR)

AF:

0.000201

AC:

AN:

44672

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26112

East Asian (EAS)

AF:

0.00

AC:

AN:

39564

South Asian (SAS)

AF:

0.00

AC:

AN:

86228

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53366

Middle Eastern (MID)

AF:

0.000174

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.0000801

AC:

AN:

1111482

Other (OTH)

AF:

0.0000331

AC:

AN:

60346

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.486

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:

0.0000460

AC:

AN:

152056

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74252

show subpopulations

African (AFR)

AF:

0.0000483

AC:

AN:

41444

American (AMR)

AF:

0.0000655

AC:

AN:

15260

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5150

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000441

AC:

AN:

67982

Other (OTH)

AF:

0.000479

AC:

AN:

2086

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

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:

0.0000868

Hom.:

Bravo

AF:

0.000106

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ExAC

AF:

0.0000579

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

ClinVar submissions as Germline

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (4)

Autosomal recessive limb-girdle muscular dystrophy type 2J (1)

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

Dilated cardiomyopathy 1G (1)

Early-onset myopathy with fatal cardiomyopathy (1)

Myopathy, myofibrillar, 9, with early respiratory failure (1)

not specified (1)

Tibial muscular dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.24

CADD

Benign

(source)

DANN

Benign

0.92

Eigen

Pathogenic

0.92

Eigen_PC

Pathogenic

0.91

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.88

M_CAP

Benign

0.018

MetaRNN

Benign

0.31

MetaSVM

Uncertain

0.25

MutationAssessor

Uncertain

2.4

PhyloP100

7.9

PrimateAI

Uncertain

0.60

PROVEAN

Benign

-0.77

REVEL

Uncertain

0.52

Sift

Benign

0.039

Polyphen

1.0

Vest4

0.27

MutPred

0.71

Loss of glycosylation at S18920 (P = 0.1507)

MVP

0.84

MPC

0.42

ClinPred

0.088

GERP RS

6.0

Mutation Taster

=64/36

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

Computational scores

Splicing

Publications

Other links and lift over