rs375657115

Variant summary

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

The NM_001267550.2(TTN):​c.94507G>A​(p.Ala31503Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000528 in 1,608,422 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). Synonymous variant affecting the same amino acid position (i.e. A31503A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000054 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

4
4
8

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7B:2

Conservation

PhyloP100: 7.91

Publications

3 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=0.13507468).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.94507G>A p.Ala31503Thr missense_variant Exon 340 of 363 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.94507G>A p.Ala31503Thr missense_variant Exon 340 of 363 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.0000460
AC:
7
AN:
152118
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000197
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:
0.0000294
Gnomad OTH
AF:
0.000956
GnomAD2 exomes
AF:
0.0000528
AC:
13
AN:
246276
AF XY:
0.0000524
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000117
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000718
Gnomad OTH exome
AF:
0.000168
GnomAD4 exome
AF:
0.0000536
AC:
78
AN:
1456188
Hom.:
0
Cov.:
34
AF XY:
0.0000567
AC XY:
41
AN XY:
723460
show subpopulations
African (AFR)
AF:
0.0000301
AC:
1
AN:
33256
American (AMR)
AF:
0.000158
AC:
7
AN:
44380
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25940
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39598
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53196
Middle Eastern (MID)
AF:
0.000174
AC:
1
AN:
5734
European-Non Finnish (NFE)
AF:
0.0000550
AC:
61
AN:
1108138
Other (OTH)
AF:
0.000133
AC:
8
AN:
60112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
6
13
19
26
32
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:
0.0000460
AC:
7
AN:
152234
Hom.:
0
Cov.:
33
AF XY:
0.0000538
AC XY:
4
AN XY:
74416
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41548
American (AMR)
AF:
0.000196
AC:
3
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5172
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10594
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68018
Other (OTH)
AF:
0.000946
AC:
2
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
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:
0.0000602
Hom.:
0
Bravo
AF:
0.0000567
TwinsUK
AF:
0.000270
AC:
1
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000121
AC:
1
ExAC
AF:
0.0000993
AC:
12
EpiCase
AF:
0.0000546
EpiControl
AF:
0.000178

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:7Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2Benign:1
Jun 04, 2019
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Dec 20, 2018
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Jun 02, 2022
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Nov 22, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Cardiomyopathy Uncertain:1
Dec 07, 2020
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9 Uncertain:1
Jan 25, 2022
New York Genome Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.94507G>A (p.Ala31503Thr) missense variant in the TTN gene has not been reported in affected individuals in the literature. The variant has 0.00005042 allele frequency in the gnomAD (v2.1.1 and v3.1.2) database (14 out of 277666 heterozygous alleles, no homozygotes)suggesting it is not a common benign variant in the populations represented in that database. This variant is reported as a variant of uncertain significance and likely benign in the ClinVar database (Variation ID: 467664). The variant affects a highly conserved residue (Ala31503) located in the A-band domain of TTN protein (PMID:25589632) and multiple in silico tools provide conflicting predictions about the potential pathogenicity of this variant (CADD score = 35, REVEL score = 0.336). Based on the available evidence, the heterozygous c.94507G>A (p.Ala31503Thr) missense variant identified in the TTN gene is reported as a Variant of Uncertain Significance.

See cases Uncertain:1
Oct 06, 2021
Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

ACMG classification criteria: BP4

Cardiovascular phenotype Uncertain:1
Jun 10, 2016
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A22438T variant (also known as c.67312G>A), located in coding exon 167 of the TTN gene, results from a G to A substitution at nucleotide position 67312. The alanine at codon 22438 is replaced by threonine, an amino acid with similar properties, and is located in the A-band region of the N2-B isoform of the titin protein. This variant was previously reported in the SNPDatabase as rs375657115. Based on data from ExAC, the A allele has an overall frequency of < 0.01% (9/103545). The highest observed frequency was 0.02%% (3/11198) of Latino alleles. Based on data from the NHLBI Exome Sequencing Project (ESP), the A allele has an overall frequency of approximately 0.01% (1/12030) total alleles studied and 0.01% (1/8236) European American alleles. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be probably damaging and tolerated by PolyPhen and SIFT in silico analyses, respectively. Since supporting evidence is limited at this time, the clinical significance of this variant remains unclear.

not specified Benign:1
Apr 09, 2025
Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.78
BayesDel_addAF
Benign
-0.17
T
BayesDel_noAF
Benign
-0.26
CADD
Benign
22
DANN
Benign
0.95
DEOGEN2
Benign
0.0
.;.;.;.;.;.;.
Eigen
Pathogenic
0.93
Eigen_PC
Pathogenic
0.92
LIST_S2
Uncertain
0.92
D;D;D;.;D;D;D
M_CAP
Benign
0.023
T
MetaRNN
Benign
0.14
T;T;T;T;T;T;T
MetaSVM
Uncertain
-0.25
T
MutationAssessor
Benign
0.0
.;.;.;M;.;.;M
PhyloP100
7.9
PrimateAI
Uncertain
0.76
T
PROVEAN
Uncertain
-2.9
D;D;.;.;D;D;.
Sift
Benign
0.036
D;D;.;.;D;D;.
Sift4G
Pathogenic
0.0
.;.;.;.;.;.;.
Vest4
0.48
ClinPred
0.13
T
GERP RS
6.0
Mutation Taster
=75/25
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: rs375657115; hg19: chr2-179411745; API