rs727504922

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP6BS1

The NM_001267550.2(TTN):​c.40408+8delA variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000249 in 1,531,222 control chromosomes in the GnomAD database, including 1 homozygotes. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00030 ( 0 hom., cov: 31)
Exomes 𝑓: 0.00024 ( 1 hom. )

Consequence

TTN
NM_001267550.2 splice_region, intron

Scores

Not classified

Clinical Significance

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

Conservation

PhyloP100: -0.0550

Publications

2 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.

BP6
Variant 2-178645911-AT-A is Benign according to our data. Variant chr2-178645911-AT-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 179522.
BS1
Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.000244 (336/1379804) while in subpopulation MID AF = 0.0068 (38/5588). AF 95% confidence interval is 0.00509. There are 1 homozygotes in GnomAdExome4. There are 174 alleles in the male GnomAdExome4 subpopulation. Median coverage is 28. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.40408+8delA splice_region_variant, intron_variant Intron 217 of 362 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.40408+8delA splice_region_variant, intron_variant Intron 217 of 362 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7

Frequencies

GnomAD3 genomes
AF:
0.000297
AC:
45
AN:
151418
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000462
Gnomad ASJ
AF:
0.00461
Gnomad EAS
AF:
0.000195
Gnomad SAS
AF:
0.000208
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.000280
Gnomad OTH
AF:
0.000482
GnomAD2 exomes
AF:
0.000406
AC:
68
AN:
167650
AF XY:
0.000433
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000538
Gnomad ASJ exome
AF:
0.00427
Gnomad EAS exome
AF:
0.0000921
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000218
Gnomad OTH exome
AF:
0.000741
GnomAD4 exome
AF:
0.000244
AC:
336
AN:
1379804
Hom.:
1
Cov.:
28
AF XY:
0.000255
AC XY:
174
AN XY:
681902
show subpopulations
African (AFR)
AF:
0.0000329
AC:
1
AN:
30354
American (AMR)
AF:
0.000450
AC:
15
AN:
33358
Ashkenazi Jewish (ASJ)
AF:
0.00448
AC:
110
AN:
24536
East Asian (EAS)
AF:
0.0000285
AC:
1
AN:
35054
South Asian (SAS)
AF:
0.0000545
AC:
4
AN:
73460
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50924
Middle Eastern (MID)
AF:
0.00680
AC:
38
AN:
5588
European-Non Finnish (NFE)
AF:
0.000121
AC:
129
AN:
1069406
Other (OTH)
AF:
0.000665
AC:
38
AN:
57124
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
13
26
38
51
64
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
10
20
30
40
50
<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:
0.000297
AC:
45
AN:
151418
Hom.:
0
Cov.:
31
AF XY:
0.000271
AC XY:
20
AN XY:
73840
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41242
American (AMR)
AF:
0.000462
AC:
7
AN:
15144
Ashkenazi Jewish (ASJ)
AF:
0.00461
AC:
16
AN:
3468
East Asian (EAS)
AF:
0.000195
AC:
1
AN:
5130
South Asian (SAS)
AF:
0.000208
AC:
1
AN:
4798
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10514
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.000280
AC:
19
AN:
67820
Other (OTH)
AF:
0.000482
AC:
1
AN:
2074
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.493
Heterozygous variant carriers
0
3
6
10
13
16
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:
0.000695
Hom.:
0
Bravo
AF:
0.000382

ClinVar

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

Submissions by phenotype

not specified Benign:4
Jul 16, 2014
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Benign based on high frequency in ESP (6% EA) -

Nov 18, 2016
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 24, 2015
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Feb 07, 2017
Eurofins Ntd Llc (ga)
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Limb-girdle muscular dystrophy, recessive Uncertain:1
Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Early-onset myopathy with fatal cardiomyopathy Uncertain:1
Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dilated Cardiomyopathy, Dominant Uncertain:1
Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Myopathy, myofibrillar, 9, with early respiratory failure Uncertain:1
Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Left ventricular noncompaction cardiomyopathy Uncertain:1
Jan 23, 2014
Blueprint Genetics
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Tibial muscular dystrophy Uncertain:1
Jun 14, 2016
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Hypertrophic cardiomyopathy Uncertain:1
Jun 14, 2016
Illumina Laboratory Services, Illumina
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 Benign:1
Jan 27, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiomyopathy Benign:1
Apr 05, 2017
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Benign:1
Mar 01, 2025
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

TTN: BP4 -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
-0.055
Mutation Taster
=100/0
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: rs727504922; hg19: chr2-179510638; API