chr2-178577664-G-A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBP6

The ENST00000589042.5(TTN):​c.68762C>T​(p.Thr22921Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000973 in 1,613,224 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00010 ( 1 hom. )

Consequence

TTN
ENST00000589042.5 missense

Scores

1
3
12

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:3

Conservation

PhyloP100: 8.09

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 -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.01642859).
BP6
Variant 2-178577664-G-A is Benign according to our data. Variant chr2-178577664-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 178998.

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000589042.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
NM_001267550.2
MANE Select
c.68762C>Tp.Thr22921Ile
missense
Exon 323 of 363NP_001254479.2
TTN
NM_001256850.1
c.63839C>Tp.Thr21280Ile
missense
Exon 273 of 313NP_001243779.1
TTN
NM_133378.4
c.61058C>Tp.Thr20353Ile
missense
Exon 272 of 312NP_596869.4

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
ENST00000589042.5
TSL:5 MANE Select
c.68762C>Tp.Thr22921Ile
missense
Exon 323 of 363ENSP00000467141.1
TTN
ENST00000446966.2
TSL:1
c.68606C>Tp.Thr22869Ile
missense
Exon 321 of 361ENSP00000408004.2
TTN
ENST00000436599.2
TSL:1
c.68486C>Tp.Thr22829Ile
missense
Exon 321 of 361ENSP00000405517.2

Frequencies

GnomAD3 genomes
AF:
0.0000657
AC:
10
AN:
152108
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:
0.00207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000214
AC:
53
AN:
247810
AF XY:
0.000320
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:
0.00
Gnomad NFE exome
AF:
0.00000893
Gnomad OTH exome
AF:
0.000667
GnomAD4 exome
AF:
0.000101
AC:
147
AN:
1460998
Hom.:
1
Cov.:
35
AF XY:
0.000154
AC XY:
112
AN XY:
726778
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33448
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:
39560
South Asian (SAS)
AF:
0.00157
AC:
135
AN:
86210
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53320
Middle Eastern (MID)
AF:
0.000521
AC:
3
AN:
5756
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111544
Other (OTH)
AF:
0.000116
AC:
7
AN:
60346
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
9
18
28
37
46
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.0000657
AC:
10
AN:
152226
Hom.:
0
Cov.:
32
AF XY:
0.000121
AC XY:
9
AN XY:
74410
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41562
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5150
South Asian (SAS)
AF:
0.00207
AC:
10
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67988
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.000257
AC:
31
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

ClinVar submissions as Germline

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

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.32
BayesDel_addAF
Benign
-0.32
T
BayesDel_noAF
Benign
-0.25
CADD
Benign
20
DANN
Benign
0.77
Eigen
Benign
-0.072
Eigen_PC
Benign
0.14
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.82
T
M_CAP
Benign
0.017
T
MetaRNN
Benign
0.016
T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.43
N
PhyloP100
8.1
PrimateAI
Uncertain
0.62
T
PROVEAN
Uncertain
-3.7
D
REVEL
Benign
0.25
Sift
Uncertain
0.0060
D
Polyphen
0.0040
B
Vest4
0.45
MutPred
0.45
Loss of disorder (P = 0.0561)
MVP
0.24
MPC
0.093
ClinPred
0.16
T
GERP RS
4.2
Mutation Taster
=80/20
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
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

Other links and lift over

dbSNP: rs534567766; hg19: chr2-179442391; API