NM_001267550.2:c.93182G>A

Variant summary

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

The NM_001267550.2(TTN):​c.93182G>A​(p.Arg31061His) variant causes a missense change. The variant allele was found at a frequency of 0.0000266 in 1,613,744 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R31061P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

2
6
8

Clinical Significance

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

Conservation

PhyloP100: 3.98

Publications

9 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=0.219096).
BP6
Variant 2-178548444-C-T is Benign according to our data. Variant chr2-178548444-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 179523.

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.93182G>Ap.Arg31061His
missense
Exon 339 of 363NP_001254479.2
TTN
NM_001256850.1
c.88259G>Ap.Arg29420His
missense
Exon 289 of 313NP_001243779.1
TTN
NM_133378.4
c.85478G>Ap.Arg28493His
missense
Exon 288 of 312NP_596869.4

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
TTN
ENST00000589042.5
TSL:5 MANE Select
c.93182G>Ap.Arg31061His
missense
Exon 339 of 363ENSP00000467141.1
TTN
ENST00000446966.2
TSL:1
c.93026G>Ap.Arg31009His
missense
Exon 337 of 361ENSP00000408004.2
TTN
ENST00000436599.2
TSL:1
c.92906G>Ap.Arg30969His
missense
Exon 337 of 361ENSP00000405517.2

Frequencies

GnomAD3 genomes
AF:
0.0000789
AC:
12
AN:
152150
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000362
AC:
9
AN:
248296
AF XY:
0.0000297
show subpopulations
Gnomad AFR exome
AF:
0.000258
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:
0.0000446
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000212
AC:
31
AN:
1461594
Hom.:
0
Cov.:
34
AF XY:
0.0000179
AC XY:
13
AN XY:
727082
show subpopulations
African (AFR)
AF:
0.000209
AC:
7
AN:
33472
American (AMR)
AF:
0.0000224
AC:
1
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53390
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000189
AC:
21
AN:
1111790
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60372
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
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
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:
0.0000789
AC:
12
AN:
152150
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74316
show subpopulations
African (AFR)
AF:
0.000241
AC:
10
AN:
41432
American (AMR)
AF:
0.0000655
AC:
1
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68022
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.488
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:
0.0000658
Hom.:
0
Bravo
AF:
0.0000491
ExAC
AF:
0.0000248
AC:
3

ClinVar

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

Submissions by phenotype

not specified Uncertain:1
Feb 17, 2014
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Arg28493His variant in TTN has not been previously reported in individuals w ith cardiomyopathy or in large population studies. Computational analyses (bioch emical amino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT) do n ot provide strong support for or against an impact to the protein. Additional in formation is needed to fully assess the clinical significance of this variant.

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Jan 05, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not provided Benign:1
Feb 10, 2020
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Cardiovascular phenotype Benign:1
Aug 31, 2020
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely 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 v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.25
BayesDel_addAF
Benign
-0.27
T
BayesDel_noAF
Benign
-0.35
CADD
Benign
23
DANN
Uncertain
0.98
Eigen
Pathogenic
0.75
Eigen_PC
Pathogenic
0.73
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.96
D
M_CAP
Benign
0.033
D
MetaRNN
Benign
0.22
T
MetaSVM
Benign
-0.36
T
MutationAssessor
Benign
1.7
L
PhyloP100
4.0
PrimateAI
Uncertain
0.53
T
PROVEAN
Uncertain
-3.4
D
REVEL
Benign
0.28
Sift
Uncertain
0.018
D
Polyphen
1.0
D
Vest4
0.42
MVP
0.26
MPC
0.49
ClinPred
0.23
T
GERP RS
5.7
Mutation Taster
=87/13
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: rs727504923; hg19: chr2-179413171; COSMIC: COSV60164458; COSMIC: COSV60164458; API