2-178751325-C-G

Variant names:

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2

The NM_133379.5(TTN):c.11075G>C(p.Ser3692Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000538 in 1,610,262 control chromosomes in the GnomAD database, including 6 homozygotes. In-silico tool predicts a benign outcome for this variant. 13/15 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00070 ( 2 hom., cov: 32)

Exomes 𝑓: 0.00052 ( 4 hom. )

Consequence

TTN
NM_133379.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:4O:1

Conservation

PhyloP100: 0.511

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 made for transcript

Verdict is Benign. Variant got -9 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0071166754).

BP6

Variant 2-178751325-C-G is Benign according to our data. Variant chr2-178751325-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 47732.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Benign=1, Uncertain_significance=2, not_provided=1}. Variant chr2-178751325-C-G is described in Lovd as [Benign].

BS2

High Homozygotes in GnomAd4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_133379.5 link	c.11075G>C	p.Ser3692Thr	missense_variant	Exon 46 of 46	ENST00000360870.10	NP_596870.2	Q8WZ42-6Q7Z3B7
TTN	NM_001267550.2 link	c.11311+1799G>C		intron_variant	Intron 47 of 362	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000360870.10 link	c.11075G>C	p.Ser3692Thr	missense_variant	Exon 46 of 46	5	NM_133379.5	ENSP00000354117.4		Q8WZ42-6
TTN	ENST00000589042.5 link	c.11311+1799G>C		intron_variant	Intron 47 of 362	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000704

AC:

107

AN:

152034

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000460

Gnomad ASJ

AF:

0.0239

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000191

Gnomad OTH

AF:

0.000479

GnomAD3 exomes

AF:

0.00107

AC:

263

AN:

246804

Hom.:

AF XY:

0.000937

AC XY:

125

AN XY:

133336

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00112

Gnomad ASJ exome

AF:

0.0186

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000233

Gnomad OTH exome

AF:

0.00283

GnomAD4 exome

AF:

0.000521

AC:

759

AN:

1458110

Hom.:

Cov.:

AF XY:

0.000509

AC XY:

369

AN XY:

725218

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00129

Gnomad4 ASJ exome

AF:

0.0193

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000999

Gnomad4 OTH exome

AF:

0.00151

GnomAD4 genome

AF:

0.000703

AC:

107

AN:

152152

Hom.:

Cov.:

AF XY:

0.000632

AC XY:

AN XY:

74398

show subpopulations

Gnomad4 AFR

AF:

0.0000722

Gnomad4 AMR

AF:

0.000459

Gnomad4 ASJ

AF:

0.0239

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000191

Gnomad4 OTH

AF:

0.000474

Alfa

AF:

0.00183

Hom.:

Bravo

AF:

0.000699

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.00128

AC:

ExAC

AF:

0.000923

AC:

112

EpiCase

AF:

0.000218

EpiControl

AF:

0.000415

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:4Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:2Benign:1

Oct 24, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant classified as Uncertain Significance - Favor Benign. The Ser3692Thr vari ant in TTN has not been reported in the literature nor previously identified by our laboratory. This variant has been identified in 0.1% (11/8598) of European A merican chromosomes from a broad population by the NHLBI Exome Sequencing Projec t (http://evs.gs.washington.edu/EVS; dbSNP rs147314430). Computational analyses are limited or unavailable for this variant. In summary, the low frequency of th is variant suggest that it is likely benign, though this is insufficient to esta blish this with certainty. Additional information is needed to fully assess the clinical significance of this variant. -

Jun 08, 2015

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Missense variants in the TTN gene are considered 'unclassified' if they are not previously reported in the literature and do not have >1% frequency in the population to be considered a polymorphism. Research indicates that truncating mutations in the TTN gene are expected to account for approximately 25% of familial and 18% of sporadic idiopathic DCM; however, truncating variants in the TTN gene have been reported in approximately 3% of reported control alleles. There has been little investigation into non-truncating variants. (Herman D et al. Truncations of titin causing dilated cardiomyopathy. N Eng J Med 366:619-628, 2012) The variant is found in CARDIOMYOPATHY panel(s). -

Oct 16, 2016

Eurofins Ntd Llc (ga)

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Benign:3

Mar 01, 2025

CeGaT Center for Human Genetics Tuebingen

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

TTN: BP4, BS1, BS2 -

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: research

- -

May 17, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

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

Other:1

GenomeConnect, ClinGen

Significance: not provided

Review Status: no classification provided

Collection Method: phenotyping only

GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.50

BayesDel_noAF

Benign

-0.54

CADD

Benign

DANN

Benign

0.61

Eigen

Benign

-0.32

Eigen_PC

Benign

-0.26

FATHMM_MKL

Uncertain

0.81

LIST_S2

Benign

0.32

M_CAP

Benign

0.015

MetaRNN

Benign

0.0071

MetaSVM

Benign

-1.1

PROVEAN

Benign

-0.90

REVEL

Benign

0.052

Sift

Benign

0.035

Sift4G

Benign

0.32

Polyphen

0.68

Vest4

0.30

MVP

0.38

ClinPred

0.057

GERP RS

2.9

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

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