rs2562847

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):​c.38753T>G​(p.Leu12918Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,612,302 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 10/12 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L12918S) has been classified as Benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 29)
Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

8

Clinical Significance

Uncertain significance no assertion criteria provided U:1

Conservation

PhyloP100: -1.21

Publications

8 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 -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.15242195).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.38753T>G p.Leu12918Trp missense_variant Exon 198 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.38753T>G p.Leu12918Trp missense_variant Exon 198 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.00000659
AC:
1
AN:
151780
Hom.:
0
Cov.:
29
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000203
AC:
5
AN:
246724
AF XY:
0.0000223
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000558
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000358
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000226
AC:
33
AN:
1460522
Hom.:
0
Cov.:
34
AF XY:
0.0000151
AC XY:
11
AN XY:
726528
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33434
American (AMR)
AF:
0.00
AC:
0
AN:
44598
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26112
East Asian (EAS)
AF:
0.0000756
AC:
3
AN:
39680
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86176
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53342
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5340
European-Non Finnish (NFE)
AF:
0.0000261
AC:
29
AN:
1111552
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60288
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.414
Heterozygous variant carriers
0
3
5
8
10
13
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:
0.00000659
AC:
1
AN:
151780
Hom.:
0
Cov.:
29
AF XY:
0.0000135
AC XY:
1
AN XY:
74088
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41370
American (AMR)
AF:
0.00
AC:
0
AN:
15166
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5136
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4798
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10574
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
310
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67964
Other (OTH)
AF:
0.00
AC:
0
AN:
2082
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.675
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
28
Bravo
AF:
0.00000378
ExAC
AF:
0.0000249
AC:
3

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: no assertion criteria provided
LINK: link

Submissions by phenotype

TTN-related disorder Uncertain:1
Aug 06, 2024
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The TTN c.38753T>G variant is predicted to result in the amino acid substitution p.Leu12918Trp. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0056% of alleles in individuals of East Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Benign
-0.37
T
BayesDel_noAF
Benign
-0.61
CADD
Benign
0.17
DANN
Benign
0.58
FATHMM_MKL
Benign
0.14
N
LIST_S2
Benign
0.42
T
M_CAP
Benign
0.0091
T
MetaRNN
Benign
0.15
T
PhyloP100
-1.2
Vest4
0.23
MVP
0.65
GERP RS
-2.6
Mutation Taster
=98/2
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs2562847; hg19: chr2-179518003; API