rs374419129

Positions:

chr2-178629302-T-G

Variant summary

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

The NM_001267550.2(TTN):c.44423A>C(p.Lys14808Thr) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000049 in 1,612,336 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000046 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense, splice_region

Scores

Splicing: ADA: 0.4905

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 2.40

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 -2 ACMG points.

PP2

Missense variant where missense usually causes diseases, TTN

BP4

Computational evidence support a benign effect (MetaRNN=0.06975299).

BP6

Variant 2-178629302-T-G is Benign according to our data. Variant chr2-178629302-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 448797.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=3}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.44423A>C	p.Lys14808Thr	missense_variant, splice_region_variant	240/363	ENST00000589042.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.44423A>C	p.Lys14808Thr	missense_variant, splice_region_variant	240/363	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.502+31621T>G		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152078

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000217

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.000479

GnomAD3 exomes

AF:

0.0000444

AC:

AN:

247552

Hom.:

AF XY:

0.0000596

AC XY:

AN XY:

134332

show subpopulations

Gnomad AFR exome

AF:

0.000194

Gnomad AMR exome

AF:

0.000204

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000328

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000459

AC:

AN:

1460140

Hom.:

Cov.:

AF XY:

0.0000523

AC XY:

AN XY:

726326

show subpopulations

Gnomad4 AFR exome

AF:

0.00111

Gnomad4 AMR exome

AF:

0.000134

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:

0.00000540

Gnomad4 OTH exome

AF:

0.000249

GnomAD4 genome

AF:

0.0000788

AC:

AN:

152196

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74394

show subpopulations

Gnomad4 AFR

AF:

0.000241

Gnomad4 AMR

AF:

0.0000654

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:

0.000474

Alfa

AF:

0.0000823

Hom.:

Bravo

AF:

0.000113

ESP6500AA

AF:

0.000253

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.0000662

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign: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	Jun 01, 2017	p.Lys12240Thr in exon 189 of TTN: This variant is not expected to have clinical significance due to a lack of conservation across species, including mammals. Of note, 5 mammals (bushbaby, naked mole rat, bat, microbat, platypus) have a thre onine (Thr) at this position. It has been identified in 7/34274 Latino chromosom es by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org/ ; dbSNP rs374419129). -
Uncertain significance, criteria provided, single submitter	clinical testing	Athena Diagnostics	Dec 31, 2016	- -

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

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 19, 2017

- -

Cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Sep 23, 2021

- -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 30, 2019

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

0.12

BayesDel_addAF

Benign

-0.33

BayesDel_noAF

Benign

-0.43

CADD

Benign

DANN

Benign

0.61

Eigen

Benign

-0.50

Eigen_PC

Benign

-0.41

FATHMM_MKL

Uncertain

0.95

LIST_S2

Benign

0.81

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

M_CAP

Benign

0.014

MetaRNN

Benign

0.070

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

MetaSVM

Benign

-0.91

MutationTaster

Benign

0.90

D;D;D;D;D;D

PrimateAI

Benign

0.38

PROVEAN

Uncertain

-3.3

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

REVEL

Benign

0.13

Sift

Benign

0.076

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

Polyphen

0.0010

.;.;.;B;.;.;B

Vest4

0.38

MVP

0.12

MPC

0.10

ClinPred

0.049

GERP RS

1.6

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.49

dbscSNV1_RF

Benign

0.55

SpliceAI score (max)

0.080

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