rs372380420

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS1

The NM_001267550.2(TTN):​c.39296-13C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000173 in 1,610,666 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00095 ( 1 hom., cov: 32)
Exomes 𝑓: 0.000091 ( 0 hom. )

Consequence

TTN
NM_001267550.2 intron

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:11

Conservation

PhyloP100: 0.0430

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: Benign. The variant received -16 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.54).
BP6
Variant 2-178651980-G-A is Benign according to our data. Variant chr2-178651980-G-A is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 178223.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000953 (145/152116) while in subpopulation AFR AF = 0.00328 (136/41516). AF 95% confidence interval is 0.00283. There are 1 homozygotes in GnomAd4. There are 71 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.39296-13C>T intron_variant Intron 204 of 362 ENST00000589042.5 NP_001254479.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.39296-13C>T intron_variant Intron 204 of 362 5 NM_001267550.2 ENSP00000467141.1

Frequencies

GnomAD3 genomes
AF:
0.000954
AC:
145
AN:
152000
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00329
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000459
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00316
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.000236
AC:
57
AN:
241980
AF XY:
0.000206
show subpopulations
Gnomad AFR exome
AF:
0.00359
Gnomad AMR exome
AF:
0.0000592
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000918
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000912
AC:
133
AN:
1458550
Hom.:
0
Cov.:
33
AF XY:
0.0000662
AC XY:
48
AN XY:
725308
show subpopulations
African (AFR)
AF:
0.00353
AC:
118
AN:
33410
American (AMR)
AF:
0.0000904
AC:
4
AN:
44252
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26048
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39444
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85806
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53242
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
0.00000270
AC:
3
AN:
1110388
Other (OTH)
AF:
0.000133
AC:
8
AN:
60204
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
Heterozygous variant carriers
0
7
15
22
30
37
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
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:
0.000953
AC:
145
AN:
152116
Hom.:
1
Cov.:
32
AF XY:
0.000955
AC XY:
71
AN XY:
74356
show subpopulations
African (AFR)
AF:
0.00328
AC:
136
AN:
41516
American (AMR)
AF:
0.000459
AC:
7
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5160
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4812
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10600
Middle Eastern (MID)
AF:
0.00340
AC:
1
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67980
Other (OTH)
AF:
0.00
AC:
0
AN:
2104
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.504
Heterozygous variant carriers
0
7
14
21
28
35
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:
0.000693
Hom.:
0
Bravo
AF:
0.00100
Asia WGS
AF:
0.000577
AC:
2
AN:
3478

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:11
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:4
Sep 10, 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. -

-
Clinical Genetics, Academic Medical Center
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jul 29, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

c.31994-13C>T in intron 158 of TTN: This variant is not expected to have clinica l significance because a C>T change at this position does not diverge from the s plice consensus sequence and is therefore unlikely to impact splicing. It has be en identified in 0.3% (26/8354) of African chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org/; dbSNP rs372380420). -

Aug 24, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: TTN c.31994-13C>T alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00024 in 241980 control chromosomes, predominantly at a frequency of 0.0036 within the African or African-American subpopulation in the gnomAD database, including 1 homozygote. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 9-fold the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.31994-13C>T in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories cited the variant as benign. Based on the evidence outlined above, the variant was classified as benign. -

not provided Benign:2
Mar 08, 2022
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
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 29, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Early-onset myopathy with fatal cardiomyopathy Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Tibial muscular dystrophy Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Sep 10, 2021
Genome-Nilou Lab
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.54
CADD
Benign
14
DANN
Benign
0.80
PhyloP100
0.043
PromoterAI
-0.024
Neutral
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: rs372380420; hg19: chr2-179516707; API