rs371924787

Variant names:

Variant summary

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

The NM_001267550.2(TTN):c.97417C>T(p.Arg32473Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000223 in 1,613,118 control chromosomes in the GnomAD database, including 1 homozygotes. 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. R32473H) has been classified as Likely benign.

Frequency

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

Exomes 𝑓: 0.000024 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 8.00

Publications

2 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: Uncertain_significance. The variant received 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.97417C>T	p.Arg32473Cys	missense_variant	Exon 349 of 363	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.97417C>T	p.Arg32473Cys	missense_variant	Exon 349 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152070

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:

0.00

Gnomad OTH

AF:

0.000480

GnomAD2 exomes

AF:

0.0000202

AC:

AN:

247778

AF XY:

0.00000744

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000291

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000268

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000240

AC:

AN:

1461048

Hom.:

Cov.:

AF XY:

0.0000275

AC XY:

AN XY:

726794

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33456

American (AMR)

AF:

0.0000224

AC:

AN:

44676

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26124

East Asian (EAS)

AF:

0.00

AC:

AN:

39564

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86200

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53372

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.0000243

AC:

AN:

1111554

Other (OTH)

AF:

0.0000829

AC:

AN:

60338

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.473

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:

0.00000658

AC:

AN:

152070

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74256

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41402

American (AMR)

AF:

0.00

AC:

AN:

15264

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5172

South Asian (SAS)

AF:

0.00

AC:

AN:

4826

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10604

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68020

Other (OTH)

AF:

0.000480

AC:

AN:

2082

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.675

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000189

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000119

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:3

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

Sep 13, 2021

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

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

Uncertain:1

Nov 06, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine with cysteine at codon 32473 of the TTN protein (p.Arg32473Cys). The arginine residue is highly conserved and there is a large physicochemical difference between arginine and cysteine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with TTN-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function are unavailable for the TTN gene. This variant identified in the TTN gene is located in the M band of the resulting protein (PMID: 25589632). It is unclear how this variant impacts the function of this protein. In summary, this variant is a novel missense change with unknown impact on protein function. Missense variants in this region of the TTN gene are typically not causative for cardiac disease, but may be relevant for neuromuscular disorders. However, the available evidence is currently insufficient to determine this variant‚Äôs role in disease. Therefore, it has been classified as a Variant of Uncertain Significance.

Cardiovascular phenotype

Uncertain:1

Dec 12, 2017

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.R23408C variant (also known as c.70222C>T), located in coding exon 176 of the TTN gene, results from a C to T substitution at nucleotide position 70222. The arginine at codon 23408 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be probably damaging and unknown by PolyPhen and SIFT in silico analyses, respectively. 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

AlphaMissense

Pathogenic

0.82

BayesDel_addAF

Uncertain

0.056

BayesDel_noAF

Uncertain

-0.060

CADD

Uncertain

(source)

DANN

Benign

0.97

DEOGEN2

Benign

0.0

.;.;.;.;.;.;.

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

1.0

LIST_S2

Uncertain

0.97

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

M_CAP

Benign

0.051

MetaRNN

Uncertain

0.61

D;D;D;D;D;D;D

MetaSVM

Uncertain

0.20

MutationAssessor

Benign

0.0

.;.;.;H;.;.;H

PhyloP100

8.0

PrimateAI

Uncertain

0.73

PROVEAN

Pathogenic

-6.0

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

Sift

Uncertain

0.0010

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

Sift4G

Pathogenic

0.0

.;.;.;.;.;.;.

Vest4

0.58

ClinPred

0.90

GERP RS

6.1

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=52/48

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over