rs77960621

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBA1

The NM_001267550.2(TTN):​c.40141+7G>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00269 in 1,549,284 control chromosomes in the GnomAD database, including 98 homozygotes. In-silico tool predicts 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 Benign (★★).

Frequency

Genomes: 𝑓 0.014 ( 46 hom., cov: 31)
Exomes 𝑓: 0.0015 ( 52 hom. )

Consequence

TTN
NM_001267550.2 splice_region, intron

Scores

2
Splicing: ADA: 0.00009394
2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:12

Conservation

PhyloP100: -0.261
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]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -20 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.83).
BP6
Variant 2-178647374-C-T is Benign according to our data. Variant chr2-178647374-C-T is described in ClinVar as [Benign]. Clinvar id is 413055.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178647374-C-T is described in Lovd as [Benign]. Variant chr2-178647374-C-T is described in Lovd as [Likely_benign].
BA1
GnomAdExome4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.051 is higher than 0.05.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.40141+7G>A splice_region_variant, intron_variant Intron 214 of 362 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.40141+7G>A splice_region_variant, intron_variant Intron 214 of 362 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0136
AC:
2068
AN:
151960
Hom.:
45
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0478
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00401
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.000193
Gnomad SAS
AF:
0.000208
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00318
Gnomad NFE
AF:
0.000132
Gnomad OTH
AF:
0.00766
GnomAD3 exomes
AF:
0.00262
AC:
389
AN:
148308
Hom.:
8
AF XY:
0.00220
AC XY:
176
AN XY:
79832
show subpopulations
Gnomad AFR exome
AF:
0.0490
Gnomad AMR exome
AF:
0.00163
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.000223
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000147
Gnomad OTH exome
AF:
0.00140
GnomAD4 exome
AF:
0.00149
AC:
2085
AN:
1397206
Hom.:
52
Cov.:
30
AF XY:
0.00131
AC XY:
904
AN XY:
689096
show subpopulations
Gnomad4 AFR exome
AF:
0.0531
Gnomad4 AMR exome
AF:
0.00165
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.000164
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000130
Gnomad4 OTH exome
AF:
0.00324
GnomAD4 genome
AF:
0.0137
AC:
2078
AN:
152078
Hom.:
46
Cov.:
31
AF XY:
0.0136
AC XY:
1009
AN XY:
74350
show subpopulations
Gnomad4 AFR
AF:
0.0479
Gnomad4 AMR
AF:
0.00400
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.000194
Gnomad4 SAS
AF:
0.000208
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000132
Gnomad4 OTH
AF:
0.00758
Alfa
AF:
0.00721
Hom.:
15
Bravo
AF:
0.0159
Asia WGS
AF:
0.00260
AC:
9
AN:
3478

ClinVar

Significance: Benign
Submissions summary: Benign:12
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Benign:4
Oct 31, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

-
Breakthrough Genomics, Breakthrough Genomics
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: not provided

- -

-
Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

not specified Benign:2
-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance: Benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

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

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

TTN-related disorder Benign:1
May 20, 2019
PreventionGenetics, part of Exact Sciences
Significance: Benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

This variant is classified as 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
Feb 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Early-onset myopathy with fatal cardiomyopathy Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Tibial muscular dystrophy Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance: 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
-0.83
CADD
Benign
0.80
DANN
Benign
0.69

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000094
dbscSNV1_RF
Benign
0.0
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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs77960621; hg19: chr2-179512101; API