rs142794598

Variant names:

Variant summary

Our verdict is Benign. Variant got -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS1

The NM_001267550.2(TTN):c.20630T>C(p.Ile6877Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00018 in 1,612,578 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0010 ( 1 hom., cov: 33)

Exomes 𝑓: 0.000094 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:10

Conservation

PhyloP100: 8.95

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 made for transcript

Verdict is Benign. Variant got -16 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.009361893).

BP6

Variant 2-178725574-A-G is Benign according to our data. Variant chr2-178725574-A-G is described in ClinVar as [Likely_benign]. Clinvar id is 178246.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178725574-A-G is described in Lovd as [Benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00101 (154/152180) while in subpopulation AFR AF= 0.00354 (147/41544). AF 95% confidence interval is 0.00307. There are 1 homozygotes in gnomad4. There are 61 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.20630T>C	p.Ile6877Thr	missense_variant	Exon 71 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.20630T>C	p.Ile6877Thr	missense_variant	Exon 71 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00102

AC:

155

AN:

152062

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00357

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000393

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:

0.000478

GnomAD3 exomes

AF:

0.000267

AC:

AN:

247418

Hom.:

AF XY:

0.000186

AC XY:

AN XY:

134172

show subpopulations

Gnomad AFR exome

AF:

0.00376

Gnomad AMR exome

AF:

0.000204

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000893

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000938

AC:

137

AN:

1460398

Hom.:

Cov.:

AF XY:

0.0000826

AC XY:

AN XY:

726396

show subpopulations

Gnomad4 AFR exome

AF:

0.00341

Gnomad4 AMR exome

AF:

0.000179

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.000116

GnomAD4 genome

AF:

0.00101

AC:

154

AN:

152180

Hom.:

Cov.:

AF XY:

0.000820

AC XY:

AN XY:

74400

show subpopulations

Gnomad4 AFR

AF:

0.00354

Gnomad4 AMR

AF:

0.000393

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000169

Hom.:

Bravo

AF:

0.00106

ESP6500AA

AF:

0.00244

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000331

AC:

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:10

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Benign:4

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: research

- -

Mar 23, 2018

Athena Diagnostics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jun 24, 2021

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is associated with the following publications: (PMID: 23861362) -

May 15, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified

Benign:3

Apr 24, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

p.Ile5633Thr in exon 68 of TTN: This variant is not expected to have clinical si gnificance because it has been identified in 0.4% (37/9774) of African chromosom es by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; db SNP rs142794598). -

Jun 23, 2023

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TTN c.16898T>C (p.Ile5633Thr) results in a non-conservative amino acid change located in the I-band of the encoded protein sequence. One of two in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00027 in 247418 control chromosomes, predominantly at a frequency of 0.0038 within the African or African-American subpopulation in the gnomAD database, including 1 homozygotes. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 9.73 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.16898T>C in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Six submitters have cited clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely benign. -

Jan 03, 2017

Eurofins Ntd Llc (ga)

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

TTN-related disorder

Benign:1

Mar 18, 2022

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely 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

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiomyopathy

Benign:1

May 16, 2023

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.25

BayesDel_addAF

Benign

-0.25

BayesDel_noAF

Benign

-0.13

CADD

Benign

DANN

Benign

0.96

Eigen

Uncertain

0.54

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Benign

0.77

T;T;.;T

M_CAP

Benign

0.078

MetaRNN

Benign

0.0094

T;T;T;T

MetaSVM

Benign

-0.39

PrimateAI

Uncertain

0.64

PROVEAN

Uncertain

-2.8

D;.;.;.

REVEL

Uncertain

0.40

Sift

Uncertain

0.013

D;.;.;.

Polyphen

0.55

.;.;P;P

Vest4

0.30

MVP

0.69

MPC

0.16

ClinPred

0.064

GERP RS

5.9

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