rs540059730

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1

The NM_001267550.2(TTN):​c.10840G>T​(p.Glu3614*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000018 in 1,613,730 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

TTN
NM_001267550.2 stop_gained

Scores

4
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.71

Publications

0 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_pathogenic. The variant received 8 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001267550.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
NM_001267550.2
MANE Select
c.10840G>Tp.Glu3614*
stop_gained
Exon 46 of 363NP_001254479.2
TTN
NM_133437.4
c.10327G>Tp.Glu3443*
stop_gained
Exon 44 of 192NP_597681.4
TTN
NM_001256850.1
c.10303+2348G>T
intron
N/ANP_001243779.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
ENST00000589042.5
TSL:5 MANE Select
c.10840G>Tp.Glu3614*
stop_gained
Exon 46 of 363ENSP00000467141.1
TTN
ENST00000446966.2
TSL:1
c.10840G>Tp.Glu3614*
stop_gained
Exon 46 of 361ENSP00000408004.2
TTN
ENST00000436599.2
TSL:1
c.10564G>Tp.Glu3522*
stop_gained
Exon 44 of 361ENSP00000405517.2

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152104
Hom.:
0
Cov.:
32
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:
0.00135
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000724
AC:
18
AN:
248622
AF XY:
0.0000593
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00100
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1461508
Hom.:
0
Cov.:
33
AF XY:
0.0000151
AC XY:
11
AN XY:
727036
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33466
American (AMR)
AF:
0.00
AC:
0
AN:
44706
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.000529
AC:
21
AN:
39664
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86244
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53390
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111778
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60368
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.507
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000460
AC:
7
AN:
152222
Hom.:
0
Cov.:
32
AF XY:
0.0000672
AC XY:
5
AN XY:
74422
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41530
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00135
AC:
7
AN:
5172
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68004
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.532
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.0000153
Hom.:
0
Bravo
AF:
0.0000264
ExAC
AF:
0.0000828
AC:
10

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Apr 25, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is located in the I band of TTN (PMID: 25589632). Truncating variants in this region have been shown to be highly prevalent in the general population and unaffected individuals (PMID: 26701604, 22335739). However, truncating variants in this region have also been reported in individuals affected with autosomal recessive centronuclear myopathy (PMID: 23975875). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant has been reported in the literature in a control individual (PMID: 28822653). ClinVar contains an entry for this variant (Variation ID: 466777). This variant is present in population databases (rs540059730, ExAC 0.1%), and has an allele count higher than expected for a pathogenic variant (PMID: 28166811). This sequence change results in a premature translational stop signal in the TTN gene (p.Glu3614*). While this is not anticipated to result in nonsense mediated decay, it is expected to create a truncated TTN protein.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.30
D
BayesDel_noAF
Pathogenic
0.60
CADD
Pathogenic
36
DANN
Uncertain
1.0
Eigen
Pathogenic
0.84
Eigen_PC
Pathogenic
0.67
FATHMM_MKL
Uncertain
0.95
D
PhyloP100
1.7
Vest4
0.76
GERP RS
4.0
Mutation Taster
=0/200
disease causing (fs/PTC)

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: rs540059730; hg19: chr2-179621363; API