chr2-178605278-A-C

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.53899T>G(p.Leu17967Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000145 in 1,586,184 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L17967M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.208

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:

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 (MetaRNN=0.13570568).

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	HGVSp	Effect	Exon Rank	Protein
TTN	NM_001267550.2	MANE Select	c.53899T>G	p.Leu17967Val	missense	Exon 280 of 363	NP_001254479.2
TTN	NM_001256850.1		c.48976T>G	p.Leu16326Val	missense	Exon 230 of 313	NP_001243779.1
TTN	NM_133378.4		c.46195T>G	p.Leu15399Val	missense	Exon 229 of 312	NP_596869.4

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
TTN	ENST00000589042.5	TSL:5 MANE Select	c.53899T>G	p.Leu17967Val	missense	Exon 280 of 363	ENSP00000467141.1
TTN	ENST00000446966.2	TSL:1	c.53743T>G	p.Leu17915Val	missense	Exon 278 of 361	ENSP00000408004.2
TTN	ENST00000436599.2	TSL:1	c.53623T>G	p.Leu17875Val	missense	Exon 278 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

151960

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000449

AC:

AN:

222608

AF XY:

0.00

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:

0.00000972

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000153

AC:

AN:

1434224

Hom.:

Cov.:

AF XY:

0.0000169

AC XY:

AN XY:

710828

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32332

American (AMR)

AF:

0.00

AC:

AN:

40842

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

24756

East Asian (EAS)

AF:

0.00

AC:

AN:

39104

South Asian (SAS)

AF:

0.00

AC:

AN:

81684

European-Finnish (FIN)

AF:

0.00

AC:

AN:

51766

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5636

European-Non Finnish (NFE)

AF:

0.0000200

AC:

AN:

1098972

Other (OTH)

AF:

0.00

AC:

AN:

59132

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.457

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

AF:

0.00000658

AC:

AN:

151960

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74210

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.0000241

AC:

AN:

41426

American (AMR)

AF:

0.00

AC:

AN:

15234

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5134

South Asian (SAS)

AF:

0.00

AC:

AN:

4818

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67934

Other (OTH)

AF:

0.00

AC:

AN:

2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.375

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.00000830

AC:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Benign

-0.092

BayesDel_noAF

Benign

-0.37

CADD

Benign

(source)

DANN

Benign

0.87

Eigen

Benign

-0.028

Eigen_PC

Benign

0.037

FATHMM_MKL

Uncertain

0.89

LIST_S2

Uncertain

0.87

M_CAP

Benign

0.038

MetaRNN

Benign

0.14

MetaSVM

Benign

-0.85

MutationAssessor

Benign

1.9

PhyloP100

0.21

PrimateAI

Uncertain

0.57

PROVEAN

Benign

-1.9

REVEL

Benign

0.092

Sift

Benign

0.076

Polyphen

0.81

Vest4

0.27

MutPred

0.41

Gain of methylation at K16325 (P = 0.0346)

MVP

0.39

MPC

0.17

ClinPred

0.14

GERP RS

3.3

Mutation Taster

=96/4

polymorphism

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.12

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

ClinVar

Computational scores

Splicing

Publications

Other links and lift over