2-178750333-C-T

Variant names:

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_133379.5(TTN):c.12067G>A(p.Gly4023Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000946 in 1,613,090 control chromosomes in the GnomAD database, including 8 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0031 ( 1 hom., cov: 32)

Exomes 𝑓: 0.00072 ( 7 hom. )

Consequence

TTN
NM_133379.5 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:11

Conservation

PhyloP100: 7.47

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 -20 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.017694652).

BP6

Variant 2-178750333-C-T is Benign according to our data. Variant chr2-178750333-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 47742.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178750333-C-T is described in Lovd as [Benign]. Variant chr2-178750333-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00309 (469/151922) while in subpopulation AFR AF= 0.00953 (395/41452). AF 95% confidence interval is 0.00875. There are 1 homozygotes in gnomad4. There are 222 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

BS2

High Homozygotes in GnomAdExome4 at 7 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_133379.5 link	c.12067G>A	p.Gly4023Arg	missense_variant	Exon 46 of 46	ENST00000360870.10	NP_596870.2	Q8WZ42-6Q7Z3B7
TTN	NM_001267550.2 link	c.11311+2791G>A		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.12067G>A	p.Gly4023Arg	missense_variant	Exon 46 of 46	5	NM_133379.5	ENSP00000354117.4		Q8WZ42-6
TTN	ENST00000589042.5 link	c.11311+2791G>A		intron_variant	Intron 47 of 362	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00309

AC:

469

AN:

151806

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00956

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00191

Gnomad ASJ

AF:

0.00635

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000236

Gnomad OTH

AF:

0.00287

GnomAD3 exomes

AF:

0.00127

AC:

319

AN:

250726

Hom.:

AF XY:

0.000967

AC XY:

131

AN XY:

135536

show subpopulations

Gnomad AFR exome

AF:

0.0106

Gnomad AMR exome

AF:

0.00122

Gnomad ASJ exome

AF:

0.00557

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000371

Gnomad OTH exome

AF:

0.000982

GnomAD4 exome

AF:

0.000723

AC:

1057

AN:

1461168

Hom.:

Cov.:

AF XY:

0.000685

AC XY:

498

AN XY:

726898

show subpopulations

Gnomad4 AFR exome

AF:

0.0104

Gnomad4 AMR exome

AF:

0.00137

Gnomad4 ASJ exome

AF:

0.00686

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000464

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000319

Gnomad4 OTH exome

AF:

0.00164

GnomAD4 genome

AF:

0.00309

AC:

469

AN:

151922

Hom.:

Cov.:

AF XY:

0.00299

AC XY:

222

AN XY:

74276

show subpopulations

Gnomad4 AFR

AF:

0.00953

Gnomad4 AMR

AF:

0.00191

Gnomad4 ASJ

AF:

0.00635

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000236

Gnomad4 OTH

AF:

0.00284

Alfa

AF:

0.000846

Hom.:

Bravo

AF:

0.00372

ESP6500AA

AF:

0.00908

AC:

ESP6500EA

AF:

0.000465

AC:

ExAC

AF:

0.00131

AC:

159

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.000600

EpiControl

AF:

0.000415

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:11

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:5

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: research

- -

Mar 20, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

p.Gly4023Arg in exon 45A of TTN: This variant is not expected to have clinical s ignificance because it has been identified in 1% (106/10394) of African chromoso mes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org/; dbSNP rs143253411). -

May 12, 2014

GeneDx

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Clinical Genetics, Academic Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not provided

Benign:3

Nov 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

TTN: PP3, BS2 -

May 07, 2021

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

TTN-related disorder

Benign:1

Sep 08, 2021

PreventionGenetics, part of Exact Sciences

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

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

Benign:1

Oct 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: 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

Benign:1

Apr 06, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Likely 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

-0.24

BayesDel_noAF

Benign

-0.10

CADD

Benign

DANN

Pathogenic

1.0

Eigen

Pathogenic

0.95

Eigen_PC

Pathogenic

0.89

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Benign

0.61

MetaRNN

Benign

0.018

MetaSVM

Uncertain

0.37

PROVEAN

Uncertain

-4.1

REVEL

Pathogenic

0.76

Sift

Pathogenic

0.0

Sift4G

Benign

0.068

Polyphen

1.0

Vest4

0.91

MutPred

0.95

Gain of MoRF binding (P = 0.013);

MVP

0.84

ClinPred

0.091

GERP RS

5.4

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