rs749931280

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PVS1_ModeratePP5

The NM_001267550.2(TTN):​c.39895+1G>T variant causes a splice donor, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,611,698 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000053 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

TTN
NM_001267550.2 splice_donor, intron

Scores

5
1
Splicing: ADA: 1.000
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2

Conservation

PhyloP100: 2.63

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: Uncertain_significance. The variant received 3 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 7.2238274E-4 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
PP5
Variant 2-178649816-C-A is Pathogenic according to our data. Variant chr2-178649816-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 223350.

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

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
NM_001267550.2
MANE Select
c.39895+1G>T
splice_donor intron
N/ANP_001254479.2Q8WZ42-12
TTN
NM_001256850.1
c.35374+1G>T
splice_donor intron
N/ANP_001243779.1Q8WZ42-1
TTN
NM_133378.4
c.32593+1G>T
splice_donor intron
N/ANP_596869.4Q8WZ42-11

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
ENST00000589042.5
TSL:5 MANE Select
c.39895+1G>T
splice_donor intron
N/AENSP00000467141.1Q8WZ42-12
TTN
ENST00000446966.2
TSL:1
c.39895+1G>T
splice_donor intron
N/AENSP00000408004.2A0A1B0GXE3
TTN
ENST00000436599.2
TSL:1
c.39619+1G>T
splice_donor intron
N/AENSP00000405517.2A0A0C4DG59

Frequencies

GnomAD3 genomes
AF:
0.0000527
AC:
8
AN:
151898
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000169
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.000480
GnomAD2 exomes
AF:
0.00000404
AC:
1
AN:
247278
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.0000647
Gnomad AMR exome
AF:
0.00
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:
0.0000110
AC:
16
AN:
1459800
Hom.:
0
Cov.:
31
AF XY:
0.0000110
AC XY:
8
AN XY:
726120
show subpopulations
African (AFR)
AF:
0.000120
AC:
4
AN:
33314
American (AMR)
AF:
0.00
AC:
0
AN:
44360
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26110
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39658
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85684
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53374
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5748
European-Non Finnish (NFE)
AF:
0.00000810
AC:
9
AN:
1111260
Other (OTH)
AF:
0.0000498
AC:
3
AN:
60292
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
1
2
4
5
6
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:
0.0000527
AC:
8
AN:
151898
Hom.:
0
Cov.:
32
AF XY:
0.0000539
AC XY:
4
AN XY:
74156
show subpopulations
African (AFR)
AF:
0.000169
AC:
7
AN:
41348
American (AMR)
AF:
0.00
AC:
0
AN:
15244
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5164
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10576
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67978
Other (OTH)
AF:
0.000480
AC:
1
AN:
2084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.519
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

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:
0.0000508
Hom.:
0
Bravo
AF:
0.0000680

ClinVar

ClinVar submissions
Significance:Conflicting classifications of pathogenicity
Revision:criteria provided, conflicting classifications
View on ClinVar
Pathogenic
VUS
Benign
Condition
1
-
-
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
-
1
-
not provided (1)
-
1
-
Primary dilated cardiomyopathy (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.40
CADD
Pathogenic
31
DANN
Uncertain
0.99
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.92
FATHMM_MKL
Pathogenic
0.98
D
PhyloP100
2.6
GERP RS
5.6
Mutation Taster
=0/100
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
1.0
Details are displayed if max score is > 0.2
DS_DL_spliceai
1.0
Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs749931280; hg19: chr2-179514543; API