2-178530739-C-T

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_StrongBP6BP7

The NM_001267550.2(TTN):​c.105876G>A​(p.Leu35292Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000116 in 1,613,920 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00011 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00012 ( 0 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:5

Conservation

PhyloP100: -1.02

Publications

1 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 -6 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.68).
BP6
Variant 2-178530739-C-T is Benign according to our data. Variant chr2-178530739-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 167753.
BP7
Synonymous conserved (PhyloP=-1.02 with no splicing effect.

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.105876G>Ap.Leu35292Leu
synonymous
Exon 358 of 363NP_001254479.2
TTN
NM_001256850.1
c.100953G>Ap.Leu33651Leu
synonymous
Exon 308 of 313NP_001243779.1
TTN
NM_133378.4
c.98172G>Ap.Leu32724Leu
synonymous
Exon 307 of 312NP_596869.4

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
ENST00000589042.5
TSL:5 MANE Select
c.105876G>Ap.Leu35292Leu
synonymous
Exon 358 of 363ENSP00000467141.1
TTN
ENST00000446966.2
TSL:1
c.105720G>Ap.Leu35240Leu
synonymous
Exon 356 of 361ENSP00000408004.2
TTN
ENST00000436599.2
TSL:1
c.105600G>Ap.Leu35200Leu
synonymous
Exon 356 of 361ENSP00000405517.2

Frequencies

GnomAD3 genomes
AF:
0.000105
AC:
16
AN:
152146
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000385
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000191
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000522
AC:
13
AN:
248880
AF XY:
0.0000296
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000167
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000887
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000118
AC:
172
AN:
1461656
Hom.:
0
Cov.:
33
AF XY:
0.000103
AC XY:
75
AN XY:
727098
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26136
East Asian (EAS)
AF:
0.0000252
AC:
1
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53388
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.000140
AC:
156
AN:
1111846
Other (OTH)
AF:
0.000215
AC:
13
AN:
60370
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.476
Heterozygous variant carriers
0
12
24
35
47
59
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
152264
Hom.:
0
Cov.:
33
AF XY:
0.0000806
AC XY:
6
AN XY:
74450
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41554
American (AMR)
AF:
0.00
AC:
0
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.000386
AC:
2
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10612
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000191
AC:
13
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.506
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:
0.000166
Hom.:
0
Bravo
AF:
0.0000756
EpiCase
AF:
0.000109
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:1Benign:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Sep 15, 2016
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Jun 24, 2019
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not specified Benign:1
Mar 19, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

p.Leu32724Leu in Exon 307 of TTN: This variant is not expected to have clinical significance because it does not alter an amino acid residue, is not located wit hin the splice consensus sequence. It has been identified in 1/6616 European Ame rican chromosomes from a broad population by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS;).

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Jan 19, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Cardiomyopathy Benign:1
Nov 24, 2017
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Cardiovascular phenotype Benign:1
Oct 15, 2020
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.68
CADD
Benign
0.082
DANN
Benign
0.60
PhyloP100
-1.0
Mutation Taster
=97/3
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: rs372521529; hg19: chr2-179395466; COSMIC: COSV100627134; COSMIC: COSV100627134; API