rs373900294

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.91434A>C​(p.Glu30478Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,613,350 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/20 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. E30478V) has been classified as Uncertain significance.

Frequency

Genomes: š‘“ 0.00011 ( 0 hom., cov: 33)
Exomes š‘“: 0.0000048 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

2
15

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:2

Conservation

PhyloP100: 0.215

Publications

2 publications found
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 was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.103978425).
BP6
Variant 2-178551097-T-G is Benign according to our data. Variant chr2-178551097-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 196155.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.91434A>C p.Glu30478Asp missense_variant Exon 336 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.91434A>C p.Glu30478Asp missense_variant Exon 336 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000105
AC:
16
AN:
152138
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000266
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000262
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:
0.000478
GnomAD2 exomes
AF:
0.0000121
AC:
3
AN:
248036
AF XY:
0.00000743
show subpopulations
Gnomad AFR exome
AF:
0.000194
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461212
Hom.:
0
Cov.:
31
AF XY:
0.00000550
AC XY:
4
AN XY:
726870
show subpopulations
African (AFR)
AF:
0.000179
AC:
6
AN:
33454
American (AMR)
AF:
0.0000224
AC:
1
AN:
44700
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39590
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86228
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53372
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111622
Other (OTH)
AF:
0.00
AC:
0
AN:
60354
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.432
Heterozygous variant carriers
0
1
2
3
4
5
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.000105
AC:
16
AN:
152138
Hom.:
0
Cov.:
33
AF XY:
0.000135
AC XY:
10
AN XY:
74320
show subpopulations
African (AFR)
AF:
0.000266
AC:
11
AN:
41430
American (AMR)
AF:
0.000262
AC:
4
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68026
Other (OTH)
AF:
0.000478
AC:
1
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.522
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000386
Hom.:
0
Bravo
AF:
0.000121
ESP6500AA
AF:
0.000507
AC:
2
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000248
AC:
3

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:1
Sep 03, 2024
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

BP4 -

Mar 31, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 20, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1Benign:1
Sep 30, 2024
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.83730A>C (p.Glu27910Asp) results in a conservative amino acid change located in the A-band (cardiodb.org) of the encoded protein sequence. Two of three in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 248036 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.83730A>C in individuals affected with Limb-Girdle Muscular Dystrophy, Type 2J and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 196155). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Apr 15, 2024
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Feb 15, 2016
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Uncertain:1
Jun 24, 2019
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.E21413D variant (also known as c.64239A>C), located in coding exon 163 of the TTN gene, results from an A to C substitution at nucleotide position 64239. The glutamic acid at codon 21413 is replaced by aspartic acid, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.091
BayesDel_addAF
Benign
-0.40
T
BayesDel_noAF
Benign
-0.52
CADD
Benign
15
DANN
Benign
0.96
Eigen
Benign
-0.50
Eigen_PC
Benign
-0.30
FATHMM_MKL
Uncertain
0.85
D
LIST_S2
Benign
0.77
T;T;T;.;T;T;T
M_CAP
Benign
0.016
T
MetaRNN
Benign
0.10
T;T;T;T;T;T;T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
-0.015
.;.;.;N;.;.;N
PhyloP100
0.21
PrimateAI
Uncertain
0.68
T
PROVEAN
Benign
-1.7
N;N;.;.;N;N;.
REVEL
Benign
0.029
Sift
Benign
0.23
T;T;.;.;T;T;.
Polyphen
0.016
.;.;.;B;.;.;B
Vest4
0.48
MutPred
0.42
.;.;.;Gain of phosphorylation at Y28840 (P = 0.1623);.;.;Gain of phosphorylation at Y28840 (P = 0.1623);
MVP
0.14
MPC
0.081
ClinPred
0.049
T
GERP RS
2.0
Mutation Taster
=73/27
polymorphism

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

Other links and lift over

dbSNP: rs373900294; hg19: chr2-179415824; COSMIC: COSV59898722; API