2-178698890-T-G

Variant summary

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

The NM_001267550.2(TTN):​c.30707A>C​(p.Asp10236Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000183 in 1,533,002 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000034 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000017 ( 1 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

5
12

Clinical Significance

Uncertain significance criteria provided, single submitter U:2

Conservation

PhyloP100: 2.29

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 -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.1410053).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.30707A>C p.Asp10236Ala missense_variant Exon 112 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.30707A>C p.Asp10236Ala missense_variant Exon 112 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.0000203
AC:
3
AN:
147806
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000747
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000134
AC:
2
AN:
149622
AF XY:
0.0000127
show subpopulations
Gnomad AFR exome
AF:
0.000125
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:
0.0000166
AC:
23
AN:
1385094
Hom.:
1
Cov.:
30
AF XY:
0.0000132
AC XY:
9
AN XY:
682644
show subpopulations
African (AFR)
AF:
0.000544
AC:
17
AN:
31222
American (AMR)
AF:
0.00
AC:
0
AN:
35090
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25058
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35756
South Asian (SAS)
AF:
0.0000133
AC:
1
AN:
75446
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
44690
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5606
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1074624
Other (OTH)
AF:
0.0000868
AC:
5
AN:
57602
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.0000338
AC:
5
AN:
147908
Hom.:
0
Cov.:
31
AF XY:
0.0000278
AC XY:
2
AN XY:
71898
show subpopulations
African (AFR)
AF:
0.000124
AC:
5
AN:
40276
American (AMR)
AF:
0.00
AC:
0
AN:
14800
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3440
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5114
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4700
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
9148
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
288
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67186
Other (OTH)
AF:
0.00
AC:
0
AN:
2046
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Jun 30, 2014
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Asp8992Ala variant in TTN has not been previously reported in individuals wi th cardiomyopathy or in large population studies. Computational prediction tools and conservation analysis do not provide strong support for or against an impac t to the protein. In summary, the clinical significance of the Asp8992Ala varian t is uncertain. -

TTN-related disorder Uncertain:1
Dec 13, 2023
PreventionGenetics, part of Exact Sciences
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

The TTN c.30707A>C variant is predicted to result in the amino acid substitution p.Asp10236Ala. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.012% of alleles in individuals of African 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
AlphaMissense
Uncertain
0.42
BayesDel_addAF
Benign
-0.19
T
BayesDel_noAF
Benign
-0.27
CADD
Benign
22
DANN
Benign
0.94
DEOGEN2
Benign
0.085
.;.;.;.;T
Eigen
Uncertain
0.26
Eigen_PC
Uncertain
0.34
FATHMM_MKL
Benign
0.73
D
LIST_S2
Benign
0.61
T;T;.;T;T
M_CAP
Benign
0.037
D
MetaRNN
Benign
0.14
T;T;T;T;T
MetaSVM
Benign
-0.52
T
PhyloP100
2.3
PrimateAI
Uncertain
0.59
T
PROVEAN
Uncertain
-3.1
D;.;.;.;D
REVEL
Benign
0.19
Sift
Benign
0.40
T;.;.;.;T
Polyphen
0.24
.;.;B;B;.
Vest4
0.39
MutPred
0.32
.;.;Gain of methylation at K9921 (P = 0.0486);Gain of methylation at K9921 (P = 0.0486);.;
MVP
0.39
MPC
0.13
ClinPred
0.15
T
GERP RS
5.5
Mutation Taster
=88/12
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: rs539986891; hg19: chr2-179563617; API