chr2-178646477-T-C

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_StrongBP6_Moderate

The NM_001267550.2(TTN):​c.40297+8A>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 0.0000313 in 1,534,822 control chromosomes in the GnomAD database, including 2 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 Likely benign (★).

Frequency

Genomes: 𝑓 0.000059 ( 1 hom., cov: 30)
Exomes 𝑓: 0.000028 ( 1 hom. )

Consequence

TTN
NM_001267550.2 splice_region, intron

Scores

2
Splicing: ADA: 0.000006763
2

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: -0.570

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=-0.93).
BP6
Variant 2-178646477-T-C is Benign according to our data. Variant chr2-178646477-T-C is described in ClinVar as Likely_benign. ClinVar VariationId is 535339.Status of the report is criteria_provided_single_submitter, 1 stars.

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.40297+8A>G
splice_region intron
N/ANP_001254479.2
TTN
NM_001256850.1
c.35375-447A>G
intron
N/ANP_001243779.1
TTN
NM_133378.4
c.32594-447A>G
intron
N/ANP_596869.4

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
ENST00000589042.5
TSL:5 MANE Select
c.40297+8A>G
splice_region intron
N/AENSP00000467141.1
TTN
ENST00000446966.2
TSL:1
c.40297+8A>G
splice_region intron
N/AENSP00000408004.2
TTN
ENST00000436599.2
TSL:1
c.40021+8A>G
splice_region intron
N/AENSP00000405517.2

Frequencies

GnomAD3 genomes
AF:
0.0000592
AC:
9
AN:
152022
Hom.:
1
Cov.:
30
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:
0.00155
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000108
AC:
16
AN:
147812
AF XY:
0.0000879
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00140
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000185
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000282
AC:
39
AN:
1382682
Hom.:
1
Cov.:
27
AF XY:
0.0000249
AC XY:
17
AN XY:
682892
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
31218
American (AMR)
AF:
0.00
AC:
0
AN:
35574
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25030
East Asian (EAS)
AF:
0.000704
AC:
25
AN:
35532
South Asian (SAS)
AF:
0.00
AC:
0
AN:
78632
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48062
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5642
European-Non Finnish (NFE)
AF:
0.0000113
AC:
12
AN:
1065550
Other (OTH)
AF:
0.0000348
AC:
2
AN:
57442
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.470
Heterozygous variant carriers
0
3
6
9
12
15
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.0000592
AC:
9
AN:
152140
Hom.:
1
Cov.:
30
AF XY:
0.0000807
AC XY:
6
AN XY:
74362
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41542
American (AMR)
AF:
0.00
AC:
0
AN:
15262
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00155
AC:
8
AN:
5148
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
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:
0.0000147
AC:
1
AN:
67966
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000680
Asia WGS
AF:
0.000578
AC:
2
AN:
3476

ClinVar

ClinVar submissions as Germline

Significance:Likely benign
Revision:criteria provided, single submitter
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
-
1
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.93
CADD
Benign
0.21
DANN
Benign
0.36
PhyloP100
-0.57
Mutation Taster
=100/0
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.0000068
dbscSNV1_RF
Benign
0.0
SpliceAI score (max)
0.010
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: rs192127273; hg19: chr2-179511204; API