rs372380420

chr2-178651980-G-A

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_StrongBP6_Very_Strong

The NM_001267550.2(TTN):c.39296-13C>T variant causes a splice polypyrimidine tract, 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 splice_polypyrimidine_tract, intron

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.0430

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:

LOC124906100 (HGNC:):

LOC124906100 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -12 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 [Likely_benign]. Clinvar id is 178223.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178651980-G-A is described in Lovd as [Benign]. Variant chr2-178651980-G-A is described in Lovd as [Likely_benign].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2 linkuse as main transcript	c.39296-13C>T		splice_polypyrimidine_tract_variant, intron_variant		ENST00000589042.5
LOC124906100	XR_007087318.1 linkuse as main transcript	n.2185+7479G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5 linkuse as main transcript	c.39296-13C>T		splice_polypyrimidine_tract_variant, intron_variant		5	NM_001267550.2	P1
TTN-AS1	ENST00000659121.1 linkuse as main transcript	n.502+54299G>A		intron_variant, non_coding_transcript_variant

Frequencies

GnomAD3 genomes

AF:

0.000954

AC:

145

AN:

152000

Hom.:

Cov.:

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

GnomAD3 exomes

AF:

0.000236

AC:

AN:

241980

Hom.:

AF XY:

0.000206

AC XY:

AN XY:

131308

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 SAS 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.:

Cov.:

AF XY:

0.0000662

AC XY:

AN XY:

725308

show subpopulations

Gnomad4 AFR exome

AF:

0.00353

Gnomad4 AMR exome

AF:

0.0000904

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.000133

GnomAD4 genome

AF:

0.000953

AC:

145

AN:

152116

Hom.:

Cov.:

AF XY:

0.000955

AC XY:

AN XY:

74356

show subpopulations

Gnomad4 AFR

AF:

0.00328

Gnomad4 AMR

AF:

0.000459

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000693

Hom.:

Bravo

AF:

0.00100

Asia WGS

AF:

0.000577

AC:

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

Benign, criteria provided, single submitter	clinical testing	GeneDx	Sep 10, 2015	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. -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Jul 29, 2015	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). -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 24, 2020	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

Likely benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Likely benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Mar 08, 2022	- -

Autosomal recessive limb-girdle muscular dystrophy type 2J

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

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

- -

Early-onset myopathy with fatal cardiomyopathy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Tibial muscular dystrophy

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Myopathy, myofibrillar, 9, with early respiratory failure

Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.54

Cadd

Benign

Dann

Benign

0.80

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.

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