2-178530023-A-G

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6

The NM_001267550.2(TTN):​c.106468T>C​(p.Tyr35490His) variant causes a missense change. The variant allele was found at a frequency of 0.0000702 in 1,609,952 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: š‘“ 0.000053 ( 0 hom., cov: 33)
Exomes š‘“: 0.000072 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

5
9
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2B:5

Conservation

PhyloP100: 4.64

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 -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.06977996).
BP6
Variant 2-178530023-A-G is Benign according to our data. Variant chr2-178530023-A-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 229572.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.106468T>C p.Tyr35490His missense_variant Exon 359 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.106468T>C p.Tyr35490His missense_variant Exon 359 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152212
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00173
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000175
AC:
43
AN:
245018
AF XY:
0.000151
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00352
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000536
Gnomad OTH exome
AF:
0.000335
GnomAD4 exome
AF:
0.0000720
AC:
105
AN:
1457740
Hom.:
0
Cov.:
32
AF XY:
0.0000759
AC XY:
55
AN XY:
724804
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33284
American (AMR)
AF:
0.00
AC:
0
AN:
43738
Ashkenazi Jewish (ASJ)
AF:
0.00300
AC:
78
AN:
26022
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39580
South Asian (SAS)
AF:
0.0000118
AC:
1
AN:
84780
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53372
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.0000189
AC:
21
AN:
1110940
Other (OTH)
AF:
0.0000830
AC:
5
AN:
60264
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
7
14
22
29
36
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
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:
0.0000526
AC:
8
AN:
152212
Hom.:
0
Cov.:
33
AF XY:
0.0000672
AC XY:
5
AN XY:
74374
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00173
AC:
6
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68020
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
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:
0.000608
Hom.:
0
Bravo
AF:
0.0000604
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000123
AC:
1
ExAC
AF:
0.000157
AC:
19
EpiCase
AF:
0.0000546
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2Benign:5
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Uncertain:1Benign:1
Apr 23, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Tyr32922His variant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 19/66630 of European chromosome s by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbS NP rs199663911). Computational prediction tools and conservation analysis do no t provide strong support for or against an impact to the protein. In summary, th e clinical significance of the p.Tyr32922His variant is uncertain. -

Feb 09, 2021
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1Benign:1
Jan 09, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is associated with the following publications: (PMID: 23861362) -

Jul 06, 2021
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Tip-toe gait Pathogenic:1
-
Practice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice Pomarino
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Myopathy refers to diseases that affect skeletal Muscles. These diseases attack muscle fibers, making muscles weak. Inherited myopathies are often caused by inheriting an abnormal gene mutation from a parent that causes the disease. Symptoms of congenital myopathies usually start at birth or in early childhood, but may not appear until the teen years or even later in adulthood. Congenital myopathies are somewhat unique compared with other inherited myopathies, as weakness typically affects all muscles and is often not progressive. Symptoms are: Muscle weakness, most commonly of upper arms and shoulders and thighs, muscle cramps, stiffness and spasms, fatigue with exertion and lack of energy. Our patients all walk on tiptoe, so they show similar symptoms. When we genetically test them with our toe walking panel, we find that around 90 per cent of them have a genetic variant that explains their toe walking. These can be assigned, for example, to the area of myopathies (such as variants of the COL6A3 gene), the area of hereditary neuropathies (such as variants of the KMT2C gene) or the area of metabolic diseases (such as variants of the PYGM gene). In a smaller group of patients with almost identical symptoms, no abnormality is found in the genes of our panel, but spastic paraplegia can be detected. In another small group of our toe walkers, no abnormalities can be detected in the genes analysed in our toe walking panel, nor do they suffer from spastic paraplegia, as is also the case with healthy children. In contrast to these, however, they show a tiptoe gait. These patients suffer from infantile cerebral palsy, in which toe walking can also be observed -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Jan 06, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Benign:1
Jan 02, 2018
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Aug 14, 2020
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.90
BayesDel_addAF
Uncertain
0.036
T
BayesDel_noAF
Uncertain
-0.030
CADD
Benign
20
DANN
Benign
0.78
Eigen
Pathogenic
0.73
Eigen_PC
Uncertain
0.63
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.86
D;D;D;.;T;D;T
M_CAP
Uncertain
0.088
D
MetaRNN
Benign
0.070
T;T;T;T;T;T;T
MetaSVM
Uncertain
0.74
D
MutationAssessor
Pathogenic
4.3
.;.;.;H;.;.;H
PhyloP100
4.6
PrimateAI
Uncertain
0.56
T
PROVEAN
Uncertain
-3.0
D;D;.;.;D;D;.
REVEL
Pathogenic
0.67
Sift
Pathogenic
0.0
.;D;.;.;D;D;.
Polyphen
0.94
.;.;.;P;.;.;P
Vest4
0.41
MVP
0.71
MPC
0.44
ClinPred
0.38
T
GERP RS
5.8
Mutation Taster
=85/15
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: rs199663911; hg19: chr2-179394750; API