chr2-178579702-G-A

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_001267550.2(TTN):​c.67495C>T​(p.Arg22499*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000031 in 1,613,046 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R22499R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000030 ( 0 hom. )

Consequence

TTN
NM_001267550.2 stop_gained

Scores

2
4

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:16

Conservation

PhyloP100: 1.60

Publications

6 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: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 2-178579702-G-A is Pathogenic according to our data. Variant chr2-178579702-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 180573.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 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

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
NM_001267550.2
MANE Select
c.67495C>Tp.Arg22499*
stop_gained
Exon 319 of 363NP_001254479.2Q8WZ42-12
TTN
NM_001256850.1
c.62572C>Tp.Arg20858*
stop_gained
Exon 269 of 313NP_001243779.1Q8WZ42-1
TTN
NM_133378.4
c.59791C>Tp.Arg19931*
stop_gained
Exon 268 of 312NP_596869.4Q8WZ42-11

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
ENST00000589042.5
TSL:5 MANE Select
c.67495C>Tp.Arg22499*
stop_gained
Exon 319 of 363ENSP00000467141.1Q8WZ42-12
TTN
ENST00000446966.2
TSL:1
c.67339C>Tp.Arg22447*
stop_gained
Exon 317 of 361ENSP00000408004.2A0A1B0GXE3
TTN
ENST00000436599.2
TSL:1
c.67219C>Tp.Arg22407*
stop_gained
Exon 317 of 361ENSP00000405517.2A0A0C4DG59

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
151822
Hom.:
0
Cov.:
32
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:
0.00
Gnomad FIN
AF:
0.000568
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000161
AC:
4
AN:
248090
AF XY:
0.0000149
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000139
Gnomad NFE exome
AF:
0.00000892
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000301
AC:
44
AN:
1461106
Hom.:
0
Cov.:
34
AF XY:
0.0000330
AC XY:
24
AN XY:
726838
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33440
American (AMR)
AF:
0.00
AC:
0
AN:
44700
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26114
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39604
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.000150
AC:
8
AN:
53394
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000324
AC:
36
AN:
1111512
Other (OTH)
AF:
0.00
AC:
0
AN:
60334
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.469
Heterozygous variant carriers
0
3
6
10
13
16
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:
0.0000395
AC:
6
AN:
151940
Hom.:
0
Cov.:
32
AF XY:
0.0000539
AC XY:
4
AN XY:
74238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41476
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:
5124
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4812
European-Finnish (FIN)
AF:
0.000568
AC:
6
AN:
10560
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67938
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
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:
0.0000220
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.0000165
AC:
2

ClinVar

ClinVar submissions
Significance:Pathogenic/Likely pathogenic
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
5
-
-
not provided (5)
3
-
-
Dilated cardiomyopathy 1G (3)
2
-
-
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy (2)
2
-
-
Primary dilated cardiomyopathy (2)
1
-
-
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
1
-
-
Cardiovascular phenotype (1)
1
-
-
Centronuclear myopathy (1)
1
-
-
Feingold syndrome type 1 (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.58
D
BayesDel_noAF
Pathogenic
0.60
CADD
Pathogenic
61
DANN
Uncertain
0.98
Eigen
Uncertain
0.65
Eigen_PC
Uncertain
0.46
FATHMM_MKL
Uncertain
0.88
D
PhyloP100
1.6
Vest4
0.98
GERP RS
4.6
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
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: rs574660186; hg19: chr2-179444429; COSMIC: COSV60149785; COSMIC: COSV60149785; API