2-178722652-T-C

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001267550.2(TTN):​c.22240+7A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000814 in 1,596,916 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000076 ( 0 hom. )

Consequence

TTN
NM_001267550.2 splice_region, intron

Scores

2
Splicing: ADA: 0.00009695
2

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: -0.221
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 made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.87).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
TTNNM_001267550.2 linkuse as main transcriptc.22240+7A>G splice_region_variant, intron_variant ENST00000589042.5

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
TTNENST00000589042.5 linkuse as main transcriptc.22240+7A>G splice_region_variant, intron_variant 5 NM_001267550.2 P1
TTN-AS1ENST00000659121.1 linkuse as main transcriptn.503-11852T>C intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152152
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000761
AC:
11
AN:
1444764
Hom.:
0
Cov.:
33
AF XY:
0.00000837
AC XY:
6
AN XY:
716858
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000725
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000453
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152152
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74316
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000207
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.87
CADD
Benign
5.8
DANN
Benign
0.49

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000097
dbscSNV1_RF
Benign
0.0
SpliceAI score (max)
0.27
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.27
Position offset: 1

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: rs368101794; hg19: chr2-179587379; API