2-178724116-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

The NM_001267550.2(TTN):c.21143G>A(p.Arg7048Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000062 in 1,612,170 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R7048L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 3.87

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:

ENSG00000267784 (HGNC:):

ENSG00000267784 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: Uncertain_significance. The variant received 0 ACMG points.

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.21143G>A	p.Arg7048Gln	missense	Exon 73 of 363	NP_001254479.2
TTN	NM_001256850.1		c.20192G>A	p.Arg6731Gln	missense	Exon 71 of 313	NP_001243779.1
TTN	NM_133378.4		c.17411G>A	p.Arg5804Gln	missense	Exon 70 of 312	NP_596869.4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTN	ENST00000589042.5	TSL:5 MANE Select	c.21143G>A	p.Arg7048Gln	missense	Exon 73 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.21143G>A	p.Arg7048Gln	missense	Exon 73 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.20867G>A	p.Arg6956Gln	missense	Exon 71 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152052

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.0000203

AC:

AN:

246444

AF XY:

0.0000150

show subpopulations

Gnomad AFR exome

AF:

0.0000648

Gnomad AMR exome

AF:

0.0000291

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000560

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000180

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000548

AC:

AN:

1460000

Hom.:

Cov.:

AF XY:

0.00000689

AC XY:

AN XY:

726082

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33414

American (AMR)

AF:

0.0000224

AC:

AN:

44630

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26074

East Asian (EAS)

AF:

0.00

AC:

AN:

39622

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86090

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53306

Middle Eastern (MID)

AF:

0.000174

AC:

AN:

5754

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1110830

Other (OTH)

AF:

0.0000166

AC:

AN:

60280

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.481

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:

0.0000131

AC:

AN:

152170

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74380

show subpopulations

African (AFR)

AF:

0.0000481

AC:

AN:

41548

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5162

South Asian (SAS)

AF:

0.00

AC:

AN:

4812

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10590

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67988

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.650

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00000931

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.0000331

AC:

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;C1858763:Dilated cardiomyopathy 1G

Uncertain:1

Dec 28, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

Sep 07, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not provided

Uncertain:1

Jun 20, 2022

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.097

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.34

CADD

Benign

(source)

DANN

Uncertain

0.99

Eigen

Uncertain

0.60

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.88

M_CAP

Benign

0.027

MetaRNN

Benign

0.21

MetaSVM

Benign

-0.55

PhyloP100

3.9

PrimateAI

Benign

0.39

PROVEAN

Benign

-1.9

REVEL

Benign

0.27

Sift

Benign

0.53

Polyphen

1.0

Vest4

0.33

MVP

0.28

MPC

0.38

ClinPred

0.27

GERP RS

6.0

Mutation Taster

=76/24

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.23

Details are displayed if max score is > 0.2

DS_AL_spliceai

0.23

Position offset: 27

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over