NM_001267550.2:c.26762-9A>G

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6

The NM_001267550.2(TTN):​c.26762-9A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000477 in 1,468,928 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 0.0000066 ( 0 hom., cov: 29)
Exomes 𝑓: 0.0000046 ( 0 hom. )

Consequence

TTN
NM_001267550.2 intron

Scores

2
Splicing: ADA: 0.00008219
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: -0.148

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 -5 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.8).
BP6
Variant 2-178713381-T-C is Benign according to our data. Variant chr2-178713381-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 229401.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.26762-9A>G intron_variant Intron 92 of 362 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.26762-9A>G intron_variant Intron 92 of 362 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.00000663
AC:
1
AN:
150898
Hom.:
0
Cov.:
29
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000661
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
GnomAD4 exome
AF:
0.00000455
AC:
6
AN:
1318030
Hom.:
0
Cov.:
32
AF XY:
0.00000467
AC XY:
3
AN XY:
641896
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
28588
American (AMR)
AF:
0.0000908
AC:
2
AN:
22038
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
21172
East Asian (EAS)
AF:
0.00
AC:
0
AN:
34336
South Asian (SAS)
AF:
0.0000160
AC:
1
AN:
62460
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
46854
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4006
European-Non Finnish (NFE)
AF:
0.00000287
AC:
3
AN:
1044272
Other (OTH)
AF:
0.00
AC:
0
AN:
54304
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.00000663
AC:
1
AN:
150898
Hom.:
0
Cov.:
29
AF XY:
0.0000136
AC XY:
1
AN XY:
73580
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
40906
American (AMR)
AF:
0.0000661
AC:
1
AN:
15134
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5068
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4738
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10480
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67810
Other (OTH)
AF:
0.00
AC:
0
AN:
2076
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.00
Hom.:
0
Bravo
AF:
0.0000227

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Uncertain:1
Oct 01, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.23030-9A>G variant in TTN has not been previously reported in individuals with cardiomyopathy or in large population studies. This variant is located in t he 3' splice region. Computational tools do not suggest an impact to splicing. H owever, this information is not predictive enough to rule out pathogenicity. In summary, the clinical significance of the c.23030-9A>G variant is uncertain. -

Cardiomyopathy Uncertain:1
Aug 27, 2021
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Jan 04, 2018
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Sep 17, 2024
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_noAF
Benign
-0.80
CADD
Benign
1.6
DANN
Benign
0.49
PhyloP100
-0.15

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000082
dbscSNV1_RF
Benign
0.0040
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: rs200821070; hg19: chr2-179578108; API