rs145527033

Variant names:

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS1

The NM_001267550.2(TTN):c.65776G>A(p.Val21926Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000181 in 1,609,610 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00080 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00012 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:12

Conservation

PhyloP100: 7.86

Publications

3 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: Benign. The variant received -16 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.008752406).

BP6

Variant 2-178583027-C-T is Benign according to our data. Variant chr2-178583027-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 202796.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000795 (121/152198) while in subpopulation AFR AF = 0.0026 (108/41566). AF 95% confidence interval is 0.0022. There are 0 homozygotes in GnomAd4. There are 61 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.65776G>A	p.Val21926Met	missense_variant	Exon 313 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.65776G>A	p.Val21926Met	missense_variant	Exon 313 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes

AF:

0.000796

AC:

121

AN:

152080

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00261

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000589

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000313

AC:

AN:

245946

AF XY:

0.000255

show subpopulations

Gnomad AFR exome

AF:

0.00287

Gnomad AMR exome

AF:

0.000733

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000359

Gnomad OTH exome

AF:

0.000336

GnomAD4 exome

AF:

0.000117

AC:

171

AN:

1457412

Hom.:

Cov.:

AF XY:

0.000112

AC XY:

AN XY:

724748

show subpopulations

African (AFR)

AF:

0.00210

AC:

AN:

33364

American (AMR)

AF:

0.000675

AC:

AN:

44450

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26010

East Asian (EAS)

AF:

0.0000254

AC:

AN:

39336

South Asian (SAS)

AF:

0.0000584

AC:

AN:

85564

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53250

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5750

European-Non Finnish (NFE)

AF:

0.0000469

AC:

AN:

1109516

Other (OTH)

AF:

0.000216

AC:

AN:

60172

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

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:

0.000795

AC:

121

AN:

152198

Hom.:

Cov.:

AF XY:

0.000820

AC XY:

AN XY:

74394

show subpopulations

African (AFR)

AF:

0.00260

AC:

108

AN:

41566

American (AMR)

AF:

0.000589

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5142

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000588

AC:

AN:

67972

Other (OTH)

AF:

0.00

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.501

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.000405

Hom.:

Bravo

AF:

0.000933

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00328

AC:

ESP6500EA

AF:

0.000120

AC:

ExAC

AF:

0.000323

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000602

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:12

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:4

Clinical Genetics, Academic Medical Center

Significance:Benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Jun 11, 2015

Eurofins Ntd Llc (ga)

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Aug 22, 2022

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

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: TTN c.58072G>A (p.Val19358Met) results in a conservative amino acid change located in the A-band of the encoded protein sequence. Three of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00031 in 245946 control chromosomes, predominantly at a frequency of 0.0029 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 7 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.58072G>A in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as likely benign. Based on the evidence outlined above, the variant was classified as benign.

Mar 19, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

p.Val19358Met in Exon 262 of TTN: This variant is not expected to have clinical significance because it has been identified in 0.3% (11/3270) of African America n chromosomes from a broad population by the NHLBI Exome Sequencing Project (htt p://evs.gs.washington.edu/EVS; dbSNP rs145527033).

not provided

Benign:4

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

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

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

Significance:Likely benign

Review Status:no assertion criteria provided

Collection Method:clinical testing

Aug 11, 2020

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Jan 16, 2019

GeneDx

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

TTN-related disorder

Benign:1

Mar 02, 2021

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

Jan 29, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Cardiomyopathy

Benign:1

Jan 20, 2023

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

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Cardiovascular phenotype

Benign:1

May 26, 2018

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.63

BayesDel_addAF

Benign

-0.26

BayesDel_noAF

Benign

-0.15

CADD

Benign

(source)

DANN

Benign

0.92

DEOGEN2

Benign

0.0

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

Eigen

Pathogenic

0.90

Eigen_PC

Pathogenic

0.85

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.93

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

M_CAP

Benign

0.029

MetaRNN

Benign

0.0088

T;T;T;T;T;T;T

MetaSVM

Uncertain

0.16

MutationAssessor

Benign

0.0

.;.;.;M;.;.;M

PhyloP100

7.9

PrimateAI

Uncertain

0.70

PROVEAN

Benign

-2.2

N;N;.;.;N;N;.

REVEL

Uncertain

0.55

Sift

Uncertain

0.011

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

Sift4G

Pathogenic

0.0

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

Vest4

0.38

ClinPred

0.035

GERP RS

5.8

Mutation Taster

=91/9

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over