rs183950862

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS1

The NM_001267550.2(TTN):​c.40223A>G​(p.Glu13408Gly) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.000227 in 1,540,880 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0012 ( 0 hom., cov: 30)
Exomes 𝑓: 0.00012 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense, splice_region

Scores

3
4
7
Splicing: ADA: 0.02789
2

Clinical Significance

Likely benign criteria provided, multiple submitters, no conflicts B:9

Conservation

PhyloP100: 3.71

Publications

2 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: Benign. The variant received -16 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.015589327).
BP6
Variant 2-178646559-T-C is Benign according to our data. Variant chr2-178646559-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 220885.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00122 (185/152186) while in subpopulation AFR AF = 0.00428 (178/41552). AF 95% confidence interval is 0.00377. There are 0 homozygotes in GnomAd4. There are 104 alleles in the male GnomAd4 subpopulation. Median coverage is 30. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.40223A>G p.Glu13408Gly missense_variant, splice_region_variant Exon 216 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.40223A>G p.Glu13408Gly missense_variant, splice_region_variant Exon 216 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.00120
AC:
183
AN:
152068
Hom.:
0
Cov.:
30
show subpopulations
Gnomad AFR
AF:
0.00425
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000328
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000196
AC:
29
AN:
147834
AF XY:
0.000138
show subpopulations
Gnomad AFR exome
AF:
0.00342
Gnomad AMR exome
AF:
0.000207
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:
0.000119
AC:
165
AN:
1388694
Hom.:
0
Cov.:
27
AF XY:
0.000112
AC XY:
77
AN XY:
685298
show subpopulations
African (AFR)
AF:
0.00408
AC:
128
AN:
31362
American (AMR)
AF:
0.000169
AC:
6
AN:
35588
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24968
East Asian (EAS)
AF:
0.00
AC:
0
AN:
35588
South Asian (SAS)
AF:
0.0000382
AC:
3
AN:
78518
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
47934
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5640
European-Non Finnish (NFE)
AF:
0.00000373
AC:
4
AN:
1071560
Other (OTH)
AF:
0.000417
AC:
24
AN:
57536
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
12
24
37
49
61
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:
0.00122
AC:
185
AN:
152186
Hom.:
0
Cov.:
30
AF XY:
0.00140
AC XY:
104
AN XY:
74384
show subpopulations
African (AFR)
AF:
0.00428
AC:
178
AN:
41552
American (AMR)
AF:
0.000328
AC:
5
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5158
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
67988
Other (OTH)
AF:
0.00
AC:
0
AN:
2108
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.514
Heterozygous variant carriers
0
10
20
31
41
51
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:
0.000646
Hom.:
1
Bravo
AF:
0.00138
TwinsUK
AF:
0.00
AC:
0
ALSPAC
AF:
0.000259
AC:
1
ExAC
AF:
0.000214
AC:
4
Asia WGS
AF:
0.000578
AC:
2
AN:
3476

ClinVar

Significance: Likely benign
Submissions summary: Benign:9
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:4
-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jun 02, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

TTN: BP4, BS1 -

not specified Benign:3
Jan 09, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.32594-529A>G is located at a position not widely known to affect splicing. This variant corresponds to c.40223A>G, p.Glu13408Gly in NM_001267550. Several computational tools predict a significant impact on normal splicing: One predicts the variant strengthens a cryptic 5' donor site. Three predict the variant strengthens a cryptic 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.0002 in 147834 control chromosomes, predominantly at a frequency of 0.0034 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 8.71 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Autosomal Recessive Titinopathy phenotype (0.00039). To our knowledge, c.32594-529A>G has not been reported in the literature in individuals affected with TTN-related conditions. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 30467950). ClinVar contains an entry for this variant (Variation ID: 220885). Based on the evidence outlined above, the variant was classified as likely benign. -

Apr 09, 2025
Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

BS1;BP1;BP6 -

-
Clinical Genetics, Academic Medical Center
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

TTN-related disorder Benign:1
Feb 18, 2020
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Jan 22, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Benign
-0.38
T
BayesDel_noAF
Benign
-0.31
CADD
Benign
22
DANN
Uncertain
0.99
Eigen
Pathogenic
0.76
Eigen_PC
Pathogenic
0.68
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Benign
0.31
T;T
M_CAP
Uncertain
0.24
D
MetaRNN
Benign
0.016
T;T
MetaSVM
Benign
-0.76
T
PhyloP100
3.7
PROVEAN
Uncertain
-4.0
.;D
REVEL
Benign
0.21
Sift
Pathogenic
0.0
.;D
Vest4
0.27
MVP
0.84
MPC
0.23
ClinPred
0.14
T
GERP RS
5.9
Mutation Taster
=25/75
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.028
dbscSNV1_RF
Benign
0.28
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: rs183950862; hg19: chr2-179511286; API