rs553668520

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_StrongBP6BS1

The NM_001267550.2(TTN):​c.91643C>T​(p.Ala30548Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000402 in 1,613,684 control chromosomes in the GnomAD database, including 1 homozygotes. 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00028 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00041 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

4
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:6O:1

Conservation

PhyloP100: 2.81
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-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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -9 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.008009225).
BP6
Variant 2-178550195-G-A is Benign according to our data. Variant chr2-178550195-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 179010.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Benign=4, Uncertain_significance=2, not_provided=1}. Variant chr2-178550195-G-A is described in Lovd as [Benign]. Variant chr2-178550195-G-A is described in Lovd as [Likely_benign].
BS1
Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.000283 (43/152196) while in subpopulation SAS AF= 0.00892 (43/4818). AF 95% confidence interval is 0.00681. There are 0 homozygotes in gnomad4. There are 28 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.91643C>T p.Ala30548Val missense_variant Exon 337 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.91643C>T p.Ala30548Val missense_variant Exon 337 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000283
AC:
43
AN:
152078
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00892
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.000877
AC:
218
AN:
248616
Hom.:
1
AF XY:
0.00109
AC XY:
147
AN XY:
134838
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000579
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00699
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000332
GnomAD4 exome
AF:
0.000414
AC:
605
AN:
1461488
Hom.:
1
Cov.:
32
AF XY:
0.000589
AC XY:
428
AN XY:
727028
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.0000447
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.0000252
Gnomad4 SAS exome
AF:
0.00641
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000450
Gnomad4 OTH exome
AF:
0.000696
GnomAD4 genome
AF:
0.000283
AC:
43
AN:
152196
Hom.:
0
Cov.:
33
AF XY:
0.000376
AC XY:
28
AN XY:
74404
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00892
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000302
Hom.:
0
Bravo
AF:
0.0000416
ExAC
AF:
0.000952
AC:
115
Asia WGS
AF:
0.00404
AC:
14
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:6Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Uncertain:1Benign:2
Jun 07, 2013
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The Ala27980Val in TTN has not been reported in individuals with cardiomyopathy or in large population studies. Computational analyses (biochemical amino acid p roperties, conservation, AlignGVGD, PolyPhen2, and SIFT) do not provide strong s upport for or against an impact to the protein. Additional information is needed to fully assess the clinical significance of this variant. -

Sep 01, 2015
Eurofins Ntd Llc (ga)
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Feb 03, 2017
Athena Diagnostics
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not provided Uncertain:1Other:1
Mar 20, 2014
GeneDx
Significance: not provided
Review Status: no classification provided
Collection Method: clinical testing

- -

Aug 01, 2016
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

TTN-related disorder Benign:1
Jun 28, 2019
PreventionGenetics, part of Exact Sciences
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

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;C1858763:Dilated cardiomyopathy 1G Benign:1
Jan 23, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Cardiomyopathy Benign:1
Mar 16, 2022
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Cardiovascular phenotype Benign:1
Sep 16, 2015
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

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
0.18
BayesDel_addAF
Benign
-0.42
T
BayesDel_noAF
Benign
-0.37
CADD
Benign
21
DANN
Uncertain
0.99
Eigen
Uncertain
0.33
Eigen_PC
Uncertain
0.46
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Benign
0.84
T;T;T;.;D;T;T
M_CAP
Benign
0.045
D
MetaRNN
Benign
0.0080
T;T;T;T;T;T;T
MetaSVM
Benign
-0.65
T
MutationAssessor
Benign
0.0
.;.;.;N;.;.;N
PrimateAI
Benign
0.45
T
PROVEAN
Benign
-2.0
N;N;.;.;N;N;.
REVEL
Benign
0.26
Sift
Benign
0.42
T;T;.;.;T;T;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.29
MutPred
0.69
.;.;.;Gain of methylation at K28906 (P = 0.0523);.;.;Gain of methylation at K28906 (P = 0.0523);
MVP
0.23
MPC
0.36
ClinPred
0.088
T
GERP RS
5.7

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.

Other links and lift over

dbSNP: rs553668520; hg19: chr2-179414922; API