rs200017524

Variant summary

Our verdict is Benign. Variant got -15 ACMG points: 1P and 16B. PP2BP4_StrongBP6_Very_StrongBS1

The NM_001267550.2(TTN):c.58612A>G(p.Thr19538Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000262 in 1,613,372 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T19538K) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0014 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 4.91

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 -15 ACMG points.

PP2

Missense variant where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.009403706).

BP6

Variant 2-178593688-T-C is Benign according to our data. Variant chr2-178593688-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 178205.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178593688-T-C is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00141 (215/152188) while in subpopulation AFR AF= 0.00465 (193/41546). AF 95% confidence interval is 0.00411. There are 0 homozygotes in gnomad4. There are 100 alleles in male gnomad4 subpopulation. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.58612A>G	p.Thr19538Ala	missense_variant	298/363	ENST00000589042.5
TTN-AS1	NR_038272.1 linkuse as main transcript	n.3364+2374T>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.58612A>G	p.Thr19538Ala	missense_variant	298/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.417-3908T>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.00141

AC:

214

AN:

152070

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00463

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000655

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:

0.00383

GnomAD3 exomes

AF:

0.000359

AC:

AN:

248186

Hom.:

AF XY:

0.000230

AC XY:

AN XY:

134632

show subpopulations

Gnomad AFR exome

AF:

0.00472

Gnomad AMR exome

AF:

0.000320

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:

0.0000445

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000142

AC:

207

AN:

1461184

Hom.:

Cov.:

AF XY:

0.000110

AC XY:

AN XY:

726866

show subpopulations

Gnomad4 AFR exome

AF:

0.00475

Gnomad4 AMR exome

AF:

0.000336

Gnomad4 ASJ exome

AF:

0.0000766

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000126

Gnomad4 OTH exome

AF:

0.000265

GnomAD4 genome

AF:

0.00141

AC:

215

AN:

152188

Hom.:

Cov.:

AF XY:

0.00134

AC XY:

100

AN XY:

74400

show subpopulations

Gnomad4 AFR

AF:

0.00465

Gnomad4 AMR

AF:

0.000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00379

Alfa

AF:

0.000681

Hom.:

Bravo

AF:

0.00153

ESP6500AA

AF:

0.00379

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000439

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3476

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

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

Likely benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Oct 31, 2015	p.Thr16970Ala in exon 247 of TTN: This variant is not expected to have clinical significance because it has been identified in 0.5% (45/9792) of African chromos omes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs200017524). -
Likely benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 08, 2015	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 11, 2018	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. -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 12, 2023	Variant summary: TTN c.50908A>G (p.Thr16970Ala) results in a non-conservative amino acid change located in the A-band region 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 0.00036 in 248186 control chromosomes, predominantly at a frequency of 0.0047 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 12-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. To our knowledge, no occurrence of c.50908A>G in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014, and all laboratories classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as benign. -

TTN-related disorder

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Nov 10, 2020

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

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

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

Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 29, 2024

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

not provided

Benign:1

Benign, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jul 20, 2018

- -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 09, 2018

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

Benign

0.10

BayesDel_addAF

Benign

-0.37

BayesDel_noAF

Benign

-0.31

Cadd

Benign

Dann

Benign

0.85

Eigen

Uncertain

0.59

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

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

M_CAP

Benign

0.018

MetaRNN

Benign

0.0094

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

MetaSVM

Benign

-0.52

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Benign

0.47

PROVEAN

Uncertain

-3.3

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

REVEL

Benign

0.25

Sift

Benign

0.10

T;T;.;.;T;T;.

Polyphen

0.90

.;.;.;P;.;.;P

Vest4

0.37

MVP

0.27

MPC

0.33

ClinPred

0.025

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