rs200166942

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2BP4_Moderate

The NM_001267550.2(TTN):c.100400T>G(p.Val33467Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000534 in 1,613,812 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00044 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00054 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:14B:5

Conservation

PhyloP100: 9.32

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 Likely_benign. Variant got -1 ACMG points.

PP2

Missense variant where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.15845618).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.100400T>G	p.Val33467Gly	missense_variant	357/363	ENST00000589042.5
TTN-AS1	NR_038272.1 linkuse as main transcript	n.316+519A>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.100400T>G	p.Val33467Gly	missense_variant	357/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.416+12711A>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000440

AC:

AN:

152228

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000851

Gnomad ASJ

AF:

0.000576

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000691

Gnomad OTH

AF:

0.000956

GnomAD3 exomes

AF:

0.000306

AC:

AN:

248550

Hom.:

AF XY:

0.000282

AC XY:

AN XY:

134842

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.000116

Gnomad ASJ exome

AF:

0.000696

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000551

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.000543

AC:

794

AN:

1461466

Hom.:

Cov.:

AF XY:

0.000546

AC XY:

397

AN XY:

727008

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000179

Gnomad4 ASJ exome

AF:

0.000804

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000658

Gnomad4 OTH exome

AF:

0.000497

GnomAD4 genome

AF:

0.000440

AC:

AN:

152346

Hom.:

Cov.:

AF XY:

0.000443

AC XY:

AN XY:

74494

show subpopulations

Gnomad4 AFR

AF:

0.0000721

Gnomad4 AMR

AF:

0.000850

Gnomad4 ASJ

AF:

0.000576

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000691

Gnomad4 OTH

AF:

0.000946

Alfa

AF:

0.000701

Hom.:

Bravo

AF:

0.000593

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000610

AC:

ExAC

AF:

0.000323

AC:

EpiCase

AF:

0.000764

EpiControl

AF:

0.000415

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:14Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:6Benign:2

Uncertain significance, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	May 31, 2018	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jun 23, 2021	This variant is associated with the following publications: (PMID: 26627873, 26438511, 28771489) -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Feb 01, 2024	TTN: BP1 -
Uncertain significance, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Uncertain significance, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Apr 06, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Feb 22, 2021	- -

Tibial muscular dystrophy

Uncertain:1Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Baylor Genetics	Aug 08, 2019	This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	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. -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Dec 23, 2014

The p.Val30899Gly variant in TTN has been identified by our laboratory in 2 Cauc asian individuals with DCM and 1 Caucasian individual with HCM. However, the ind ividual with HCM also carried another pathogenic variant that was sufficient to explain their disease. The p.Val30899Gly variant has also been identified in 40/ 67148 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exa c.broadinstitute.org; dbSNP rs200166942). Computational prediction tools and con servation analysis do not provide strong support for or against an impact to the protein. In summary, the clinical significance of the p.Val30899Gly variant is uncertain. -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 30, 2017

- -

Dilated cardiomyopathy 1G

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

Cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Jul 14, 2017

- -

Early-onset myopathy with fatal cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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. -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 10, 2020

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

0.90

BayesDel_addAF

Benign

0.0096

BayesDel_noAF

Uncertain

0.13

Cadd

Benign

Dann

Benign

0.90

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.97

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Benign

0.82

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

M_CAP

Uncertain

0.20

MetaRNN

Benign

0.16

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

MetaSVM

Uncertain

0.78

MutationTaster

Benign

1.0

D;D;D;D;D;D

PrimateAI

Uncertain

0.72

PROVEAN

Pathogenic

-5.3

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

REVEL

Pathogenic

0.86

Sift

Uncertain

0.0010

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

Polyphen

1.0

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

Vest4

0.44

MVP

0.86

MPC

0.53

ClinPred

0.17

GERP RS

5.8

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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