NM_001267550.2:c.28754A>C

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):​c.28754A>C​(p.Glu9585Ala) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000825 in 1,575,204 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E9585G) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense, splice_region

Scores

2
14
Splicing: ADA: 0.01874
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.03

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: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.13283041).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.28754A>C p.Glu9585Ala missense_variant, splice_region_variant Exon 100 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.28754A>C p.Glu9585Ala missense_variant, splice_region_variant Exon 100 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.0000591
AC:
9
AN:
152200
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000217
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:
0.00
GnomAD2 exomes
AF:
0.00000439
AC:
1
AN:
227618
AF XY:
0.00000811
show subpopulations
Gnomad AFR exome
AF:
0.0000661
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:
0.00000281
AC:
4
AN:
1423004
Hom.:
0
Cov.:
31
AF XY:
0.00000142
AC XY:
1
AN XY:
702574
show subpopulations
African (AFR)
AF:
0.000125
AC:
4
AN:
32070
American (AMR)
AF:
0.00
AC:
0
AN:
39580
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
24542
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39096
South Asian (SAS)
AF:
0.00
AC:
0
AN:
80910
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52702
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5600
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1090006
Other (OTH)
AF:
0.00
AC:
0
AN:
58498
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.412
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000591
AC:
9
AN:
152200
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.000217
AC:
9
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
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:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.464
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:
0.0000416

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not specified Uncertain:1
Sep 14, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The Glu8341Ala variant in TTN has not been reported in the literature nor previo usly identified by our laboratory. This variant has been identified in 1/3678 Af rican American chromosomes from a broad population by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/; dbSNP rs200856239), though this cou ld represent a presymptomatic individual. Computational analyses (biochemical am ino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT) do not provid e strong support for or against an impact to the protein though it should be not ed that the variant amino acid (alanine, Ala) is present in one species (zebrafi sh). This variant is located in the first base of the exon, which is part of the 3? splice region. Computational tools do not suggest an impact to splicing, tho ugh this information is not predictive enough to rule out pathogenicity. Additio nal information is needed to fully assess the clinical significance of this vari ant. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.40
CADD
Benign
22
DANN
Benign
0.95
Eigen
Benign
-0.14
Eigen_PC
Benign
0.028
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Benign
0.71
T;T;.;T
M_CAP
Benign
0.029
D
MetaRNN
Benign
0.13
T;T;T;T
MetaSVM
Benign
-1.1
T
PhyloP100
4.0
PrimateAI
Benign
0.46
T
PROVEAN
Uncertain
-3.4
D;.;.;.
REVEL
Benign
0.10
Sift
Benign
0.12
T;.;.;.
Polyphen
0.0030
.;.;B;B
Vest4
0.22
MutPred
0.36
.;.;Loss of disorder (P = 0.064);Loss of disorder (P = 0.064);
MVP
0.17
MPC
0.090
ClinPred
0.21
T
GERP RS
4.2
Mutation Taster
=47/53
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.019
dbscSNV1_RF
Benign
0.11
SpliceAI score (max)
0.060
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: rs200856239; hg19: chr2-179572540; API