chr2-178525997-T-C

Variant names:

Variant summary

Our verdict is The variant received -3 classification points (ACMG Germline Pathogenicity v2019). BP4_ModerateBP6

The NM_001267550.2(TTN):c.*1015A>G variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a cumulative frequency of 0.00295 (AC=450) in the gnomAD database across 152,344 control chromosomes, including 3 homozygotes. The grpmax filtering allele frequency (95% CI) is 0.00562. In-silico predictor (BayesDel (noAF)) classifies this variant as likely benign. Splicing prediction tools (SpliceAI) predict no significant impact on normal splicing. Variant has been reported in ClinVar as Benign/Likely Benign (no review stars).

Frequency

Genomes: 𝑓 0.0030 ( 3 hom., cov: 33)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

TTN
NM_001267550.2 3_prime_UTR

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 7.11

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 Gene-Disease associations (from GenCC):

dilated cardiomyopathy 1G
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
myopathy, myofibrillar, 9, with early respiratory failure
Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet, ClinGen
early-onset myopathy with fatal cardiomyopathy
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)
TTN-related myopathy
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
tibial muscular dystrophy
Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet, ClinGen
autosomal recessive limb-girdle muscular dystrophy type 2J
Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics
TTN-related myopathy, dominant-negative TTNsv
Inheritance: AD Classification: MODERATE Submitted by: ClinGen
familial isolated dilated cardiomyopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
autosomal recessive centronuclear myopathy
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
arrhythmogenic right ventricular cardiomyopathy
Inheritance: AD Classification: LIMITED, NO_KNOWN Submitted by: ClinGen, G2P
congenital myopathy
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
familial hypertrophic cardiomyopathy
Inheritance: AD Classification: LIMITED Submitted by: G2P
hereditary skeletal muscle disorder
Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics
hypertrophic cardiomyopathy
Inheritance: AD Classification: LIMITED Submitted by: ClinGen
hypertrophic cardiomyopathy 9
Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

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

new If you want to explore the variant's impact on the transcript NM_001267550.2, check out the Mutation Effect Viewer. This is especially useful for frameshift variants or if you want to visualize the effect of exon loss / intron retention.

Classification according to ACMG Germline Pathogenicity v2019

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 points.

BP4

Computational evidence supports benign — no pathogenic computational or splicing signal (BP4); Splicing verdict: benign (Strong).; Germline computational verdict: benign (Moderate).

BP6

ClinVar 0-star benign — supporting (BP6); ClinVar germline classification: Benign/Likely Benign, 0 star(s).

Variant Effect in Transcripts

Automated classification analysis was done for transcript: NM_001267550.2. You can select a different transcript below to see updated classification assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein	UniProt
TTN	NM_001267550.2	MANE Select	c.*1015A>G	3_prime_UTR	Exon 363 of 363	NP_001254479.2	Q8WZ42-12
TTN	NM_001256850.1		c.*1015A>G	3_prime_UTR	Exon 313 of 313	NP_001243779.1	Q8WZ42-1
TTN	NM_133378.4		c.*1015A>G	3_prime_UTR	Exon 312 of 312	NP_596869.4	Q8WZ42-11

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein	UniProt
TTN	ENST00000589042.5	TSL:5 MANE Select	c.*1015A>G	3_prime_UTR	Exon 363 of 363	ENSP00000467141.1	Q8WZ42-12
TTN	ENST00000446966.2	TSL:1	c.*1015A>G	3_prime_UTR	Exon 361 of 361	ENSP00000408004.2	A0A1B0GXE3
TTN	ENST00000436599.2	TSL:1	c.*1015A>G	3_prime_UTR	Exon 361 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes

AF:

0.00296

AC:

450

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000362

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00668

Gnomad ASJ

AF:

0.0268

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00165

Gnomad FIN

AF:

0.000282

Gnomad MID

AF:

0.0127

Gnomad NFE

AF:

0.00303

Gnomad OTH

AF:

0.00907

GnomAD4 exome

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

414

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

252

African (AFR)

AC:

AN:

American (AMR)

AC:

AN:

Ashkenazi Jewish (ASJ)

AC:

AN:

East Asian (EAS)

AC:

AN:

South Asian (SAS)

AC:

AN:

European-Finnish (FIN)

AF:

0.00

AC:

AN:

406

Middle Eastern (MID)

AC:

AN:

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

Other (OTH)

AF:

0.00

AC:

AN:

GnomAD4 genome

AF:

0.00295

AC:

450

AN:

152344

Hom.:

Cov.:

AF XY:

0.00274

AC XY:

204

AN XY:

74494

show subpopulations

African (AFR)

AF:

0.000361

AC:

AN:

41576

American (AMR)

AF:

0.00667

AC:

102

AN:

15300

Ashkenazi Jewish (ASJ)

AF:

0.0268

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00165

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.000282

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.0136

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00303

AC:

206

AN:

68028

Other (OTH)

AF:

0.00898

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.514

Heterozygous variant carriers

110

137

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Genome Hom

Variant carriers

<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:

0.00327

Hom.:

Bravo

AF:

0.00334

Asia WGS

AF:

0.00115

AC:

AN:

3478

Local populations

Turkish Variome

AF:

0.0129

AC:

AN:

1546

Hom.:

ABraOM SABE-WGS-1171

AF:

0.00512

AC:

AN:

2342

Hom.:

ClinVar

ClinVar submissions

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

Autosomal recessive limb-girdle muscular dystrophy type 2J (1)

Dilated cardiomyopathy 1G (1)

Early-onset myopathy with fatal cardiomyopathy (1)

Myopathy, myofibrillar, 9, with early respiratory failure (1)

Tibial muscular dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.29

CADD

Benign

(source)

DANN

Benign

0.89

PhyloP100

7.1

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

Classification according to ACMG Germline Pathogenicity v2019

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Local populations

ClinVar

Computational scores

Splicing

Publications

Other links and lift over