rs761362832

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 0P and 0B.

The NM_001267550.2(TTN):​c.99518G>A​(p.Cys33173Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000273 in 1,613,626 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C33173S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

9
5
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7O:1

Conservation

PhyloP100: 7.91
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 Uncertain_significance. Variant got 0 ACMG points.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.99518G>A p.Cys33173Tyr missense_variant Exon 355 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.99518G>A p.Cys33173Tyr missense_variant Exon 355 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152152
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000197
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:
0.0000522
AC:
13
AN:
248920
Hom.:
0
AF XY:
0.0000444
AC XY:
6
AN XY:
135038
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000319
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:
0.00000886
Gnomad OTH exome
AF:
0.000166
GnomAD4 exome
AF:
0.0000274
AC:
40
AN:
1461474
Hom.:
0
Cov.:
33
AF XY:
0.0000275
AC XY:
20
AN XY:
727010
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.000403
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:
0.0000180
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000263
AC:
4
AN:
152152
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74318
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.000197
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
Bravo
AF:
0.0000378
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ExAC
AF:
0.0000579
AC:
7
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:7Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:3Other:1
Dec 01, 2023
CeGaT Center for Human Genetics Tuebingen
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

TTN: PP3 -

Jan 12, 2018
Eurofins Ntd Llc (ga)
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jun 03, 2014
GeneDx
Significance: not provided
Review Status: no classification provided
Collection Method: clinical testing

- -

Jun 24, 2020
Athena Diagnostics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

not specified Uncertain:2
Mar 02, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Variant summary: TTN c.91814G>A (p.Cys30605Tyr) results in a non-conservative amino acid change located in the I-band region of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 5.2e-05 in 248920 control chromosomes, predominantly at a frequency of 0.00032 within the Latino subpopulation in the gnomAD database (exomes dataset). This frequency is somewhat lower than the maximum expected for a pathogenic variant in TTN causing Cardiomyopathy (0.00032 vs 0.00063), allowing no conclusion about variant significance. To our knowledge, no occurrence of c.91814G>A in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

May 06, 2020
Genetic Services Laboratory, University of Chicago
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.91814G>A sequence change results in an amino acid change, p.Cys30605Tyr. This sequence change has been described in the gnomAD database with a low population frequency of 0.005223% (dbSNP rs761362832). The p.Cys30605Tyr change affects a highly conserved amino acid residue located in a domain of the TTN protein that is known to be functional. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Cys30605Tyr substitution. This sequence change does not appear to have been previously described in patients with TTN-related disorders. Due to the lack of sufficient evidence, the clinical significance of the p.Cys30605Tyr change remains unknown at this time. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Nov 08, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Brugada syndrome Uncertain:1
Dec 24, 2018
Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Benign
-0.017
T
BayesDel_noAF
Uncertain
0.040
CADD
Benign
22
DANN
Benign
0.94
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.94
D;D;D;.;D;D;D
M_CAP
Pathogenic
0.32
D
MetaRNN
Uncertain
0.69
D;D;D;D;D;D;D
MetaSVM
Uncertain
0.65
D
MutationAssessor
Pathogenic
4.7
.;.;.;H;.;.;H
PrimateAI
Pathogenic
0.83
D
PROVEAN
Pathogenic
-7.5
D;D;.;.;D;D;.
REVEL
Pathogenic
0.76
Sift
Uncertain
0.0040
D;D;.;.;D;D;.
Polyphen
1.0
.;.;.;D;.;.;D
Vest4
0.64
MutPred
0.78
.;.;.;Gain of phosphorylation at C31532 (P = 0.0869);.;.;Gain of phosphorylation at C31532 (P = 0.0869);
MVP
0.77
MPC
0.60
ClinPred
0.34
T
GERP RS
5.9
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7

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: rs761362832; hg19: chr2-179402416; API