2-178681074-T-G

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):c.33340+5A>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000204 in 1,595,866 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 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 0.000099 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00022 ( 0 hom. )

Consequence

TTN
NM_001267550.2 splice_region, intron

Scores

Splicing: ADA: 0.02373

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:2

Conservation

PhyloP100: 1.71

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 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 was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.31).

Variant Effect in Transcripts

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

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein
TTN	NM_001267550.2	MANE Select	c.33340+5A>C	splice_region intron	N/A	NP_001254479.2
TTN	NM_001256850.1		c.32389+5A>C	splice_region intron	N/A	NP_001243779.1
TTN	NM_133378.4		c.29608+5A>C	splice_region intron	N/A	NP_596869.4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	Effect	Exon Rank	Protein
TTN	ENST00000589042.5	TSL:5 MANE Select	c.33340+5A>C	splice_region intron	N/A	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.33340+5A>C	splice_region intron	N/A	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.33064+5A>C	splice_region intron	N/A	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.0000986

AC:

AN:

152076

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000191

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000724

AC:

AN:

234966

AF XY:

0.0000942

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000156

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000215

AC:

311

AN:

1443790

Hom.:

Cov.:

AF XY:

0.000213

AC XY:

153

AN XY:

717828

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32256

American (AMR)

AF:

0.00

AC:

AN:

40566

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25694

East Asian (EAS)

AF:

0.00

AC:

AN:

39506

South Asian (SAS)

AF:

0.00

AC:

AN:

81768

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53188

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5726

European-Non Finnish (NFE)

AF:

0.000276

AC:

305

AN:

1105364

Other (OTH)

AF:

0.000100

AC:

AN:

59722

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.436

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

100

<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:

0.0000986

AC:

AN:

152076

Hom.:

Cov.:

AF XY:

0.000121

AC XY:

AN XY:

74296

show subpopulations

African (AFR)

AF:

0.0000483

AC:

AN:

41444

American (AMR)

AF:

0.00

AC:

AN:

15250

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000191

AC:

AN:

67950

Other (OTH)

AF:

0.00

AC:

AN:

2088

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.472

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

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:

0.000112

Hom.:

Bravo

AF:

0.000110

EpiCase

AF:

0.000165

EpiControl

AF:

0.000120

ClinVar

ClinVar submissions as Germline

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (2)

not specified (2)

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

Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9 (1)

TTN-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.31

CADD

Benign

(source)

DANN

Benign

0.94

PhyloP100

1.7

Mutation Taster

=79/21

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.024

dbscSNV1_RF

Benign

0.23

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over