rs368938701

Positions:

chr2-178575165-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_001267550.2(TTN):c.70967C>T(p.Pro23656Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,612,534 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

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

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 9.94

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 made for transcript

Verdict is Uncertain_significance. Variant got 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.39387208).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.70967C>T	p.Pro23656Leu	missense_variant	326/363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.70967C>T	p.Pro23656Leu	missense_variant	326/363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152038

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1460496

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

726484

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:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152038

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74252

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

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:

0.0000329

Hom.:

Bravo

AF:

0.0000189

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000121

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jan 16, 2013

The Pro21088Leu variant in TTN has not been reported in the literature nor previ ously identified by our laboratory. This variant has been identified in 1/8298 E uropean American chromosomes from a broad population by the NHLBI Exome Sequenci ng Project (http://evs.gs.washington.edu/EVS/). Computational analyses (biochemi cal amino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT) do not provide strong support for or against an impact to the protein. In summary, addi tional information is needed to fully assess the clinical significance of the Pr o21088Leu variant -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Mar 02, 2023

Not observed at significant frequency in large population cohorts (gnomAD); Missense variant in a gene in which most reported pathogenic variants are truncating/loss of function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.48

BayesDel_addAF

Uncertain

0.071

BayesDel_noAF

Benign

-0.14

CADD

Benign

DANN

Benign

0.93

Eigen

Pathogenic

0.89

Eigen_PC

Pathogenic

0.87

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.95

D;D;D;.;D;D;D

M_CAP

Benign

0.034

MetaRNN

Benign

0.39

T;T;T;T;T;T;T

MetaSVM

Uncertain

-0.019

MutationAssessor

Uncertain

2.4

.;.;.;M;.;.;M

PrimateAI

Uncertain

0.70

PROVEAN

Pathogenic

-7.5

D;D;.;.;D;D;.

REVEL

Uncertain

0.51

Sift

Uncertain

0.0020

D;D;.;.;D;D;.

Polyphen

1.0

.;.;.;D;.;.;D

Vest4

0.41

MVP

0.73

MPC

0.47

ClinPred

0.81

GERP RS

5.5

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

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