rs72648946

Variant names:

Variant summary

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

The NM_001267550.2(TTN):c.17989G>A(p.Ala5997Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000995 in 1,613,328 control chromosomes in the GnomAD database, including 14 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0053 ( 7 hom., cov: 33)

Exomes 𝑓: 0.00055 ( 7 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:22

Conservation

PhyloP100: 7.91

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=0.010351807).

BP6

Variant 2-178730544-C-T is Benign according to our data. Variant chr2-178730544-C-T is described in ClinVar as [Likely_benign]. Clinvar id is 46635.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178730544-C-T is described in Lovd as [Benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0053 (807/152248) while in subpopulation AFR AF= 0.0186 (772/41562). AF 95% confidence interval is 0.0175. There are 7 homozygotes in gnomad4. There are 377 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAd4 at 7 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.17989G>A	p.Ala5997Thr	missense_variant	Exon 61 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.17989G>A	p.Ala5997Thr	missense_variant	Exon 61 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00530

AC:

806

AN:

152130

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0186

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00144

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:

0.0000882

Gnomad OTH

AF:

0.00335

GnomAD3 exomes

AF:

0.00132

AC:

329

AN:

248614

Hom.:

AF XY:

0.000882

AC XY:

119

AN XY:

134896

show subpopulations

Gnomad AFR exome

AF:

0.0191

Gnomad AMR exome

AF:

0.000754

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:

0.0000444

Gnomad OTH exome

AF:

0.000332

GnomAD4 exome

AF:

0.000547

AC:

799

AN:

1461080

Hom.:

Cov.:

AF XY:

0.000461

AC XY:

335

AN XY:

726778

show subpopulations

Gnomad4 AFR exome

AF:

0.0200

Gnomad4 AMR exome

AF:

0.000940

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:

0.0000270

Gnomad4 OTH exome

AF:

0.000961

GnomAD4 genome

AF:

0.00530

AC:

807

AN:

152248

Hom.:

Cov.:

AF XY:

0.00506

AC XY:

377

AN XY:

74434

show subpopulations

Gnomad4 AFR

AF:

0.0186

Gnomad4 AMR

AF:

0.00144

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000882

Gnomad4 OTH

AF:

0.00331

Alfa

AF:

0.00110

Hom.:

Bravo

AF:

0.00599

ESP6500AA

AF:

0.0195

AC:

ESP6500EA

AF:

0.000121

AC:

ExAC

AF:

0.00154

AC:

186

Asia WGS

AF:

0.00115

AC:

AN:

3478

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:22

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Benign:6

Mar 02, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Ala4753Thr in exon 58 of TTN: This variant is not expected to have clinical sign ificance because it has been identified in 2.0% (65/3204) of African American ch romosomes from a broad population by the NHLBI Exome Sequencing Project (http:// evs.gs.washington.edu/EVS; dbSNP rs72648946). -

Jul 09, 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 DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Nov 11, 2020

Athena Diagnostics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Clinical Genetics, Academic Medical Center

Significance: Benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Apr 12, 2020

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

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:2

Sep 10, 2021

Genome-Nilou Lab

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Cardiomyopathy

Benign:2

Apr 17, 2019

Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 15, 2017

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

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:2

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Sep 10, 2021

Genome-Nilou Lab

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Benign:2

Breakthrough Genomics, Breakthrough Genomics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

Jul 29, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Tibial muscular dystrophy

Benign:2

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

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:2

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Sep 10, 2021

Genome-Nilou Lab

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

TTN-related disorder

Benign:1

Jul 15, 2019

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

Feb 02, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dilated cardiomyopathy 1G

Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Cardiovascular phenotype

Benign:1

Mar 01, 2013

Ambry Genetics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as benign based on a combination of the following: 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

0.62

BayesDel_addAF

Benign

-0.40

BayesDel_noAF

Benign

-0.34

CADD

Benign

DANN

Benign

0.96

Eigen

Pathogenic

0.95

Eigen_PC

Pathogenic

0.93

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.82

T;T;.;T

MetaRNN

Benign

0.010

T;T;T;T

MetaSVM

Uncertain

-0.030

PrimateAI

Uncertain

0.53

PROVEAN

Benign

-2.0

N;.;.;.

REVEL

Uncertain

0.44

Sift

Benign

0.22

T;.;.;.

Polyphen

1.0

.;.;D;D

Vest4

0.43

MVP

0.43

MPC

0.39

ClinPred

0.035

GERP RS

6.0

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