2-178658281-C-T

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001267550.2(TTN):​c.37702G>A​(p.Ala12568Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. In-silico tool predicts a benign outcome for this variant. 12/15 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 10)
Exomes 𝑓: 0.000034 ( 0 hom. )
Failed GnomAD Quality Control

Consequence

TTN
NM_001267550.2 missense

Scores

11

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: -5.59

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_benign. The variant received -4 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.057545424).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.37702G>A p.Ala12568Thr missense_variant Exon 185 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.37702G>A p.Ala12568Thr missense_variant Exon 185 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000113
AC:
9
AN:
79932
Hom.:
0
Cov.:
10
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00263
Gnomad AMR
AF:
0.000169
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:
0.000167
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000602
AC:
3
AN:
49816
AF XY:
0.0000792
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000111
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000103
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.0000335
AC:
27
AN:
804886
Hom.:
0
Cov.:
11
AF XY:
0.0000341
AC XY:
14
AN XY:
410264
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.000115
AC:
2
AN:
17442
American (AMR)
AF:
0.0000472
AC:
1
AN:
21194
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
18134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
33562
South Asian (SAS)
AF:
0.0000184
AC:
1
AN:
54414
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
31150
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
2736
European-Non Finnish (NFE)
AF:
0.0000391
AC:
23
AN:
588348
Other (OTH)
AF:
0.00
AC:
0
AN:
37906
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000000588714), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.355
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
Data not reliable, filtered out with message: AS_VQSR
AF:
0.000113
AC:
9
AN:
79932
Hom.:
0
Cov.:
10
AF XY:
0.000163
AC XY:
6
AN XY:
36838
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
18810
American (AMR)
AF:
0.000169
AC:
1
AN:
5928
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2316
East Asian (EAS)
AF:
0.00
AC:
0
AN:
3082
South Asian (SAS)
AF:
0.00
AC:
0
AN:
1802
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
4546
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
222
European-Non Finnish (NFE)
AF:
0.000167
AC:
7
AN:
41910
Other (OTH)
AF:
0.00
AC:
0
AN:
936
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.264
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:
0.000759
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Aug 07, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy Uncertain:1
Sep 03, 2021
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Benign
-0.47
T
BayesDel_noAF
Benign
-0.68
CADD
Benign
0.19
DANN
Benign
0.76
Eigen
Benign
-1.1
Eigen_PC
Benign
-1.2
FATHMM_MKL
Benign
0.017
N
LIST_S2
Benign
0.29
T
M_CAP
Benign
0.018
T
MetaRNN
Benign
0.058
T
MetaSVM
Benign
-1.0
T
PhyloP100
-5.6
Vest4
0.063
MVP
0.11
MPC
0.081
ClinPred
0.042
T
GERP RS
1.1
Mutation Taster
=95/5
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
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: rs1060500468; hg19: chr2-179523008; API