rs201735487

Positions:

chr2-178757842-G-C

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4_StrongBP6

The NM_001267550.2(TTN):c.10378C>G(p.Pro3460Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000944 in 1,589,766 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/16 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. P3460P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00049 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000053 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:7

Conservation

PhyloP100: 0.404

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 -4 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TTN. . Gene score misZ -1.1021 (greater than the threshold 3.09). Trascript score misZ 6.9794 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, tibial muscular dystrophy, early-onset myopathy with fatal cardiomyopathy, autosomal recessive centronuclear myopathy, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 9, TTN-related myopathy, dilated cardiomyopathy 1G, arrhythmogenic right ventricular cardiomyopathy, myopathy, myofibrillar, 9, with early respiratory failure, familial isolated dilated cardiomyopathy, childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome, autosomal recessive limb-girdle muscular dystrophy type 2J.

BP4

Computational evidence support a benign effect (MetaRNN=0.0061867237).

BP6

Variant 2-178757842-G-C is Benign according to our data. Variant chr2-178757842-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 166289.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=1, Benign=5}. Variant chr2-178757842-G-C is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.10378C>G	p.Pro3460Ala	missense_variant	45/363	ENST00000589042.5
TTN	NM_133379.5 linkuse as main transcript	c.10303+1142C>G		intron_variant		ENST00000360870.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.10378C>G	p.Pro3460Ala	missense_variant	45/363	5	NM_001267550.2	P1
TTN	ENST00000360870.10 linkuse as main transcript	c.10303+1142C>G		intron_variant		5	NM_133379.5		Q8WZ42-6
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.1281-1149G>C		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000486

AC:

AN:

152144

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00164

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.00191

GnomAD3 exomes

AF:

0.000135

AC:

AN:

229334

Hom.:

AF XY:

0.000113

AC XY:

AN XY:

124348

show subpopulations

Gnomad AFR exome

AF:

0.00178

Gnomad AMR exome

AF:

0.0000657

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:

0.00

Gnomad OTH exome

AF:

0.000370

GnomAD4 exome

AF:

0.0000529

AC:

AN:

1437504

Hom.:

Cov.:

AF XY:

0.0000463

AC XY:

AN XY:

713220

show subpopulations

Gnomad4 AFR exome

AF:

0.00195

Gnomad4 AMR exome

AF:

0.0000735

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:

9.09e-7

Gnomad4 OTH exome

AF:

0.000152

GnomAD4 genome

AF:

0.000486

AC:

AN:

152262

Hom.:

Cov.:

AF XY:

0.000510

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.00164

Gnomad4 AMR

AF:

0.000131

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:

0.00189

Alfa

AF:

0.000158

Hom.:

Bravo

AF:

0.000563

ESP6500AA

AF:

0.00216

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000174

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:7

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:1Benign:2

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 20, 2023	Variant summary: TTN c.10303+1142C>G is located at a position not widely known to affect splicing. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00014 in 229334 control chromosomes, predominantly at a frequency of 0.0018 within the African or African-American subpopulation in the gnomAD database. To our knowledge, no occurrence of c.10303+1142C>G in individuals affected with Limb-Girdle Muscular Dystrophy, Type 2J and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 12, 2014	This variant is not expected to have clinical significance because the variant a minoacid is present in 13 other mammals and the variant has been identified in 0 .2% (8/3704) of African American chromosomes by the NHLBI Exome Sequencing Proje ct (http://evs.gs.washington.edu/EVS/; dbSNP rs201735487). -
Likely benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	May 08, 2017	- -

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

Likely benign, criteria provided, single submitter

clinical testing

Invitae

Feb 01, 2024

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

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

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Benign

-0.59

BayesDel_noAF

Benign

-0.62

CADD

Benign

DANN

Benign

0.61

Eigen

Benign

-0.89

Eigen_PC

Benign

-0.84

FATHMM_MKL

Benign

0.068

LIST_S2

Benign

0.36

T;T

M_CAP

Benign

0.012

MetaRNN

Benign

0.0062

T;T

MetaSVM

Benign

-0.98

MutationTaster

Benign

1.0

D;D;D;D;D;N;N

PROVEAN

Benign

-0.65

.;N

REVEL

Benign

0.048

Sift

Benign

0.67

.;T

Vest4

0.23

MVP

0.12

MPC

0.081

ClinPred

0.0036

GERP RS

-2.1

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