dbSNP rs28933405: TTN:p.Arg740Leu (chr2-178785999-C-A) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP5

The NM_001267550.2(TTN):c.2219G>T(p.Arg740Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,822 control chromosomes in the GnomAD database, with no homozygous occurrence. 12/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Pathogenic no assertion criteria provided P:1

Conservation

PhyloP100: 0.627

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:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 2-178785999-C-A is Pathogenic according to our data. Variant chr2-178785999-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 12649.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr2-178785999-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.2219G>T	p.Arg740Leu	missense_variant	Exon 14 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7
TTN	NM_133379.5 link	c.2219G>T	p.Arg740Leu	missense_variant	Exon 14 of 46	ENST00000360870.10	NP_596870.2	Q8WZ42-6Q7Z3B7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.2219G>T	p.Arg740Leu	missense_variant	Exon 14 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7
TTN	ENST00000360870.10 link	c.2219G>T	p.Arg740Leu	missense_variant	Exon 14 of 46	5	NM_133379.5	ENSP00000354117.4		Q8WZ42-6

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461822

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727212

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

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:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

LINK: link

Submissions by phenotype

Hypertrophic cardiomyopathy 9

Pathogenic:1

Aug 27, 1999

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.12

BayesDel_addAF

Uncertain

0.068

BayesDel_noAF

Benign

-0.14

CADD

Benign

8.0

DANN

Benign

0.36

Eigen

Benign

-1.1

Eigen_PC

Benign

-1.0

FATHMM_MKL

Benign

0.66

LIST_S2

Uncertain

0.87

D;D;D;.;D;D;T;D

M_CAP

Benign

0.029

MetaRNN

Uncertain

0.56

D;D;D;D;D;D;D;D

MetaSVM

Benign

-0.95

PrimateAI

Benign

0.22

PROVEAN

Benign

-2.0

N;N;.;.;N;N;.;N

REVEL

Uncertain

0.32

Sift

Benign

0.067

T;D;.;.;T;T;.;D

Sift4G

Benign

0.45

.;.;.;.;.;.;.;T

Polyphen

0.0, 0.0010

.;.;.;B;.;.;B;B

Vest4

0.51

MutPred

0.47

Loss of phosphorylation at S742 (P = 0.0497);.;Loss of phosphorylation at S742 (P = 0.0497);Loss of phosphorylation at S742 (P = 0.0497);.;.;Loss of phosphorylation at S742 (P = 0.0497);Loss of phosphorylation at S742 (P = 0.0497);

MVP

0.21

MPC

0.10

ClinPred

0.074

GERP RS

1.2

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