2-178764172-C-T

Position:

chr2-178764172-C-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_ModerateBP6BS1BS2

The NM_001267550.2(TTN):c.10114+5G>A variant causes a splice donor 5th base, intron change. The variant allele was found at a frequency of 0.000937 in 1,614,058 control chromosomes in the GnomAD database, including 8 homozygotes. In-silico tool predicts a benign outcome for this variant. 2/3 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 0.0031 ( 1 hom., cov: 33)

Exomes 𝑓: 0.00071 ( 7 hom. )

Consequence

TTN
NM_001267550.2 splice_donor_5th_base, intron

Scores

Splicing: ADA: 0.9974

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:20

Conservation

PhyloP100: 4.41

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 links:

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]

TTN-AS1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -11 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.21).

BP6

Variant 2-178764172-C-T is Benign according to our data. Variant chr2-178764172-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46579.We mark this variant Likely_benign, oryginal submissions are: {Benign=10, Likely_benign=7, Uncertain_significance=1}. Variant chr2-178764172-C-T is described in Lovd as [Benign]. Variant chr2-178764172-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0031 (472/152274) while in subpopulation AFR AF= 0.00958 (398/41564). AF 95% confidence interval is 0.0088. There are 1 homozygotes in gnomad4. There are 221 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAdExome4 at 7 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.10114+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000589042.5
TTN	NM_133379.5 linkuse as main transcript	c.10114+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000360870.10

Ensembl

Gene	Transcript	HGVSc	Effect	TSL	MANE	Appris	UniProt
TTN	ENST00000360870.10 linkuse as main transcript	c.10114+5G>A	splice_donor_5th_base_variant, intron_variant	5	NM_133379.5		Q8WZ42-6
TTN	ENST00000589042.5 linkuse as main transcript	c.10114+5G>A	splice_donor_5th_base_variant, intron_variant	5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.1410-14C>T	splice_polypyrimidine_tract_variant, intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.00310

AC:

472

AN:

152156

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00960

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00190

Gnomad ASJ

AF:

0.00634

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00316

Gnomad NFE

AF:

0.000235

Gnomad OTH

AF:

0.00287

GnomAD3 exomes

AF:

0.00127

AC:

318

AN:

251358

Hom.:

AF XY:

0.000964

AC XY:

131

AN XY:

135844

show subpopulations

Gnomad AFR exome

AF:

0.0105

Gnomad AMR exome

AF:

0.00121

Gnomad ASJ exome

AF:

0.00556

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000369

Gnomad OTH exome

AF:

0.000978

GnomAD4 exome

AF:

0.000711

AC:

1040

AN:

1461784

Hom.:

Cov.:

AF XY:

0.000671

AC XY:

488

AN XY:

727206

show subpopulations

Gnomad4 AFR exome

AF:

0.0101

Gnomad4 AMR exome

AF:

0.00136

Gnomad4 ASJ exome

AF:

0.00689

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000319

Gnomad4 OTH exome

AF:

0.00156

GnomAD4 genome

AF:

0.00310

AC:

472

AN:

152274

Hom.:

Cov.:

AF XY:

0.00297

AC XY:

221

AN XY:

74446

show subpopulations

Gnomad4 AFR

AF:

0.00958

Gnomad4 AMR

AF:

0.00190

Gnomad4 ASJ

AF:

0.00634

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000235

Gnomad4 OTH

AF:

0.00284

Alfa

AF:

0.00214

Hom.:

Bravo

AF:

0.00371

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.000600

EpiControl

AF:

0.000415

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:20

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Benign:8

Benign, criteria provided, single submitter	clinical testing	GeneDx	May 12, 2014	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. -
Likely benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Dec 31, 2013	- -
Benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Aug 06, 2015	- -
Benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Nov 09, 2020	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 20, 2015	c.10114+5G>A in Intron 43 of TTN: This variant is not expected to have clinical significance because it has been identified in 1% (106/10380) of African chromos omes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org/; dbSNP rs115985443). -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Sep 14, 2019	- -

not provided

Benign:4

Likely benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	May 07, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2024	TTN: BP4, BS2 -
Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Likely benign, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G

Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Feb 01, 2024

- -

Dilated cardiomyopathy 1G

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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

Benign, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Mar 02, 2016

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

Cardiovascular phenotype

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 14, 2012

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. -

TTN-related myopathy

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Molecular Genetics, Royal Melbourne Hospital

Nov 05, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.21

CADD

Benign

DANN

Benign

0.95

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Benign

0.69

SpliceAI score (max)

0.080

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over