chr2-178653276-A-G

Variant names:

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBA1

The NM_001267550.2(TTN):c.38753T>C(p.Leu12918Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0686 in 151,694 control chromosomes in the GnomAD database, including 531 homozygotes. In-silico tool predicts a benign outcome for this variant. 9/11 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L12918W) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.069 ( 531 hom., cov: 29)

Exomes 𝑓: 0.064 ( 4827 hom. )

Failed GnomAD Quality Control

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:10

Conservation

PhyloP100: -1.21

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:

LOC124906100 (HGNC:):

LOC124906100 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0048615634).

BP6

Variant 2-178653276-A-G is Benign according to our data. Variant chr2-178653276-A-G is described in ClinVar as [Benign]. Clinvar id is 535163.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178653276-A-G is described in Lovd as [Benign].

BA1

GnomAd4 highest subpopulation (SAS) allele frequency at 95% confidence interval = 0.178 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.38753T>C	p.Leu12918Ser	missense_variant	Exon 198 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.38753T>C	p.Leu12918Ser	missense_variant	Exon 198 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.0686

AC:

10391

AN:

151574

Hom.:

525

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0432

Gnomad AMI

AF:

0.0727

Gnomad AMR

AF:

0.160

Gnomad ASJ

AF:

0.0449

Gnomad EAS

AF:

0.119

Gnomad SAS

AF:

0.189

Gnomad FIN

AF:

0.101

Gnomad MID

AF:

0.0484

Gnomad NFE

AF:

0.0478

Gnomad OTH

AF:

0.0567

GnomAD2 exomes

AF:

0.102

AC:

25221

AN:

246724

AF XY:

0.101

show subpopulations

Gnomad AFR exome

AF:

0.0434

Gnomad AMR exome

AF:

0.224

Gnomad ASJ exome

AF:

0.0420

Gnomad EAS exome

AF:

0.129

Gnomad FIN exome

AF:

0.104

Gnomad NFE exome

AF:

0.0492

Gnomad OTH exome

AF:

0.0842

GnomAD4 exome

Data not reliable, filtered out with message: AS_VQSR

AF:

0.0637

AC:

92795

AN:

1457244

Hom.:

4827

Cov.:

AF XY:

0.0666

AC XY:

48253

AN XY:

725010

show subpopulations

Gnomad4 AFR exome

AF:

0.0425

AC:

1419

AN:

33356

Gnomad4 AMR exome

AF:

0.217

AC:

9584

AN:

44204

Gnomad4 ASJ exome

AF:

0.0410

AC:

1069

AN:

26082

Gnomad4 EAS exome

AF:

0.107

AC:

4252

AN:

39644

Gnomad4 SAS exome

AF:

0.186

AC:

15941

AN:

85812

Gnomad4 FIN exome

AF:

0.107

AC:

5717

AN:

53290

Gnomad4 NFE exome

AF:

0.0456

AC:

50548

AN:

1109366

Gnomad4 Remaining exome

AF:

0.0668

AC:

4021

AN:

60170

Heterozygous variant carriers

4553

9106

13660

18213

22766

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Exome Het

Exome Hom

Variant carriers

2146

4292

6438

8584

10730

<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:

0.0686

AC:

10406

AN:

151694

Hom.:

531

Cov.:

AF XY:

0.0753

AC XY:

5583

AN XY:

74106

show subpopulations

Gnomad4 AFR

AF:

0.0432

AC:

0.0431825

AN:

0.0431825

Gnomad4 AMR

AF:

0.161

AC:

0.16074

AN:

0.16074

Gnomad4 ASJ

AF:

0.0449

AC:

0.0449309

AN:

0.0449309

Gnomad4 EAS

AF:

0.120

AC:

0.119922

AN:

0.119922

Gnomad4 SAS

AF:

0.189

AC:

0.188628

AN:

0.188628

Gnomad4 FIN

AF:

0.101

AC:

0.101383

AN:

0.101383

Gnomad4 NFE

AF:

0.0478

AC:

0.0478365

AN:

0.0478365

Gnomad4 OTH

AF:

0.0561

AC:

0.0560837

AN:

0.0560837

Heterozygous variant carriers

444

888

1331

1775

2219

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Genome Het

Genome Hom

Variant carriers

124

248

372

496

620

<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:

0.0325

Hom.:

ExAC

AF:

0.0965

AC:

11621

ClinVar

Significance: Benign

Submissions summary: Benign:10

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:3

Dec 17, 2018

Athena Diagnostics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jun 26, 2018

GeneDx

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Breakthrough Genomics, Breakthrough Genomics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:not provided

- -

not specified

Benign:2

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

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

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

Benign:1

Feb 04, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Tibial muscular dystrophy

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Sep 10, 2021

Genome-Nilou Lab

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.72

BayesDel_noAF

Benign

-0.67

CADD

Benign

0.12

DANN

Benign

0.53

FATHMM_MKL

Benign

0.080

LIST_S2

Benign

0.17

MetaRNN

Benign

0.0049

Vest4

0.024

GERP RS

-2.6

Mutation Taster

=98/2

polymorphism (auto)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.070

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over