rs144672482

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 1P and 3B. PP2BP4_ModerateBP6

The NM_001267550.2(TTN):c.4261C>T(p.Arg1421Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000613 in 1,613,922 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1421Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000055 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:2

Conservation

PhyloP100: 0.213

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:

LOC101927055 (HGNC:):

LOC101927055 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PP2

Missense variant where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.07383111).

BP6

Variant 2-178777923-G-A is Benign according to our data. Variant chr2-178777923-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 178271.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
TTN	NM_001267550.2 linkuse as main transcript	c.4261C>T	p.Arg1421Trp	missense_variant	25/363	ENST00000589042.5
TTN	NM_133379.5 linkuse as main transcript	c.4261C>T	p.Arg1421Trp	missense_variant	25/46	ENST00000360870.10
LOC101927055	NR_120594.1 linkuse as main transcript	n.998G>A		non_coding_transcript_exon_variant	1/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.4261C>T	p.Arg1421Trp	missense_variant	25/363	5	NM_001267550.2	P1
TTN	ENST00000360870.10 linkuse as main transcript	c.4261C>T	p.Arg1421Trp	missense_variant	25/46	5	NM_133379.5		Q8WZ42-6
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.5350G>A		non_coding_transcript_exon_variant	12/13

Frequencies

GnomAD3 genomes

AF:

0.000118

AC:

AN:

152176

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000410

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000639

AC:

AN:

250374

Hom.:

AF XY:

0.0000665

AC XY:

AN XY:

135346

show subpopulations

Gnomad AFR exome

AF:

0.000369

Gnomad AMR exome

AF:

0.00

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:

0.0000797

Gnomad OTH exome

AF:

0.000164

GnomAD4 exome

AF:

0.0000554

AC:

AN:

1461628

Hom.:

Cov.:

AF XY:

0.0000550

AC XY:

AN XY:

727114

show subpopulations

Gnomad4 AFR exome

AF:

0.000418

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000558

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.000118

AC:

AN:

152294

Hom.:

Cov.:

AF XY:

0.000148

AC XY:

AN XY:

74468

show subpopulations

Gnomad4 AFR

AF:

0.000409

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000237

Hom.:

Bravo

AF:

0.000144

ESP6500AA

AF:

0.000681

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000741

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:1Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Oct 10, 2018	The p.Arg1421Trp variant in TTN is classified as likely benign because it has be en identified in 0.05% (12/24020) of African chromosomes by gnomAD (http://gnoma d.broadinstitute.org). ACMG/AMP Criteria applied: BS1. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Apr 29, 2014	- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 06, 2017

- -

not provided

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Mar 03, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.77

BayesDel_addAF

Benign

-0.28

BayesDel_noAF

Benign

-0.26

Cadd

Benign

Dann

Benign

0.86

Eigen

Benign

-0.37

Eigen_PC

Benign

-0.44

FATHMM_MKL

Uncertain

0.94

LIST_S2

Uncertain

0.94

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

M_CAP

Benign

0.014

MetaRNN

Benign

0.074

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

MetaSVM

Benign

-0.54

MutationTaster

Benign

0.58

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

PrimateAI

Uncertain

0.77

PROVEAN

Uncertain

-3.2

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

REVEL

Uncertain

0.29

Sift

Uncertain

0.019

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

Polyphen

1.0, 1.0

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

Vest4

0.30

MVP

0.22

MPC

0.25

ClinPred

0.12

GERP RS

0.39

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