rs56137037

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_001267550.2(TTN):​c.426C>T​(p.Ala142Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00244 in 1,614,108 control chromosomes in the GnomAD database, including 59 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.0020 ( 7 hom., cov: 32)
Exomes 𝑓: 0.0025 ( 52 hom. )

Consequence

TTN
NM_001267550.2 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:24

Conservation

PhyloP100: -2.00
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.61).
BP6
Variant 2-178800552-G-A is Benign according to our data. Variant chr2-178800552-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 47044.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178800552-G-A is described in Lovd as [Benign]. Variant chr2-178800552-G-A is described in Lovd as [Likely_benign].
BP7
Synonymous conserved (PhyloP=-2 with no splicing effect.
BS1
Variant frequency is greater than expected in population sas. gnomad4 allele frequency = 0.00202 (307/152262) while in subpopulation SAS AF= 0.0253 (122/4822). AF 95% confidence interval is 0.0217. There are 7 homozygotes in gnomad4. There are 176 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
BS2
High Homozygotes in GnomAd4 at 7 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TTNNM_001267550.2 linkc.426C>T p.Ala142Ala synonymous_variant Exon 4 of 363 ENST00000589042.5 NP_001254479.2 A0A0A0MTS7
TTNNM_133379.5 linkc.426C>T p.Ala142Ala synonymous_variant Exon 4 of 46 ENST00000360870.10 NP_596870.2 Q8WZ42-6Q7Z3B7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TTNENST00000589042.5 linkc.426C>T p.Ala142Ala synonymous_variant Exon 4 of 363 5 NM_001267550.2 ENSP00000467141.1 A0A0A0MTS7
TTNENST00000360870.10 linkc.426C>T p.Ala142Ala synonymous_variant Exon 4 of 46 5 NM_133379.5 ENSP00000354117.4 Q8WZ42-6

Frequencies

GnomAD3 genomes
AF:
0.00199
AC:
303
AN:
152144
Hom.:
6
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000169
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00190
Gnomad ASJ
AF:
0.00691
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.0245
Gnomad FIN
AF:
0.0000943
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00178
Gnomad OTH
AF:
0.00144
GnomAD3 exomes
AF:
0.00422
AC:
1060
AN:
251330
Hom.:
15
AF XY:
0.00526
AC XY:
715
AN XY:
135816
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.000809
Gnomad ASJ exome
AF:
0.00833
Gnomad EAS exome
AF:
0.0000544
Gnomad SAS exome
AF:
0.0229
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00194
Gnomad OTH exome
AF:
0.00391
GnomAD4 exome
AF:
0.00248
AC:
3631
AN:
1461846
Hom.:
52
Cov.:
31
AF XY:
0.00315
AC XY:
2288
AN XY:
727228
show subpopulations
Gnomad4 AFR exome
AF:
0.000418
Gnomad4 AMR exome
AF:
0.000738
Gnomad4 ASJ exome
AF:
0.00781
Gnomad4 EAS exome
AF:
0.000101
Gnomad4 SAS exome
AF:
0.0222
Gnomad4 FIN exome
AF:
0.0000562
Gnomad4 NFE exome
AF:
0.00112
Gnomad4 OTH exome
AF:
0.00320
GnomAD4 genome
AF:
0.00202
AC:
307
AN:
152262
Hom.:
7
Cov.:
32
AF XY:
0.00236
AC XY:
176
AN XY:
74450
show subpopulations
Gnomad4 AFR
AF:
0.000168
Gnomad4 AMR
AF:
0.00190
Gnomad4 ASJ
AF:
0.00691
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.0253
Gnomad4 FIN
AF:
0.0000943
Gnomad4 NFE
AF:
0.00178
Gnomad4 OTH
AF:
0.00142
Alfa
AF:
0.00168
Hom.:
1
Bravo
AF:
0.00127
Asia WGS
AF:
0.00924
AC:
32
AN:
3478
EpiCase
AF:
0.00294
EpiControl
AF:
0.00302

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:24
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:7
Apr 19, 2012
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Ala142Ala in exon 4 of TTN: This variant is not expected to have clinical signif icance because it does not alter an amino acid residue, is not located within th e splice consensus sequence, and has been identified in 0.26% (18/7020) of Europ ean American chromosomes from a broad population by the NHLBI Exome Sequencing P roject (http://evs.gs.washington.edu/EVS; dbSNP rs56137037). Ala142Ala in exon 4 of TTN (allele frequency = 0.26%, 18/7020; dbSNP rs56137037) ** -

Jan 20, 2014
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. -

Nov 04, 2019
Athena Diagnostics
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Sep 01, 2015
Eurofins Ntd Llc (ga)
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

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

- -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance: Benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Oct 08, 2019
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.426C>T alters a non-conserved nucleotide resulting in a synonymous change. 5/5 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 0.0042 in 251330 control chromosomes, predominantly at a frequency of 0.023 within the South Asian subpopulation in the gnomAD database, including 14 homozygotes. The observed variant frequency within South Asian control individuals in the gnomAD database is approximately 37-folds over the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Cardiomyopathy phenotype (0.00063), strongly suggesting that the variant is a benign polymorphism found primarily in populations of South Asian origin. Four ClinVar submissions (evaluation after 2014) cite the variant three times as benign and once as uncertain significance. Based on the evidence outlined above, the variant was classified as benign. -

not provided Benign:5
-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Nov 14, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance: 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

- -

-
Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)
Significance: Likely benign
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

-
Breakthrough Genomics, Breakthrough Genomics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: not provided

- -

Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:2
Sep 10, 2021
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Early-onset myopathy with fatal cardiomyopathy Benign:2
Sep 10, 2021
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Tibial muscular dystrophy Benign:2
Sep 10, 2021
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:2
Sep 10, 2021
Genome-Nilou Lab
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Benign:1
Feb 02, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Dilated cardiomyopathy 1G Benign:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Cardiomyopathy Benign:1
Mar 29, 2017
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Cardiovascular phenotype Benign:1
Dec 28, 2012
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: 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 v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.61
CADD
Benign
3.7
DANN
Benign
0.57

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs56137037; hg19: chr2-179665279; API