NM_001267550.2:c.29938G>A

Variant names:

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_001267550.2(TTN):c.29938G>A(p.Ala9980Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000198 in 1,611,366 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00031 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00019 ( 2 hom. )

Consequence

TTN
NM_001267550.2 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:5

Conservation

PhyloP100: 6.42

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 made for transcript

Verdict is Benign. Variant got -13 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0070787966).

BP6

Variant 2-178704534-C-T is Benign according to our data. Variant chr2-178704534-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 46827.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Benign=1, Uncertain_significance=1}. Variant chr2-178704534-C-T is described in Lovd as [Likely_benign].

BS1

Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.000309 (47/152282) while in subpopulation EAS AF= 0.00578 (30/5190). AF 95% confidence interval is 0.00416. There are 0 homozygotes in gnomad4. There are 26 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck.

BS2

High Homozygotes in GnomAdExome4 at 2 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2 link	c.29938G>A	p.Ala9980Thr	missense_variant	Exon 105 of 363	ENST00000589042.5	NP_001254479.2	A0A0A0MTS7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5 link	c.29938G>A	p.Ala9980Thr	missense_variant	Exon 105 of 363	5	NM_001267550.2	ENSP00000467141.1		A0A0A0MTS7

Frequencies

GnomAD3 genomes

AF:

0.000315

AC:

AN:

152164

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.0143

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00596

Gnomad SAS

AF:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000622

AC:

154

AN:

247416

Hom.:

AF XY:

0.000596

AC XY:

AN XY:

134122

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00798

Gnomad SAS exome

AF:

0.000300

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000889

Gnomad OTH exome

AF:

0.000167

GnomAD4 exome

AF:

0.000186

AC:

272

AN:

1459084

Hom.:

Cov.:

AF XY:

0.000185

AC XY:

134

AN XY:

725428

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00585

Gnomad4 SAS exome

AF:

0.000210

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000117

Gnomad4 OTH exome

AF:

0.000133

GnomAD4 genome

AF:

0.000309

AC:

AN:

152282

Hom.:

Cov.:

AF XY:

0.000349

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00578

Gnomad4 SAS

AF:

0.000414

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000256

Hom.:

Bravo

AF:

0.000400

ExAC

AF:

0.000612

AC:

Asia WGS

AF:

0.00115

AC:

AN:

3478

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:5

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not specified

Uncertain:1Benign:2

Jan 31, 2017

Eurofins Ntd Llc (ga)

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 09, 2016

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 13, 2012

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant classified as Uncertain Significance - Favor Benign. The Ala8736Thr vari ant in TTN has been identified in 0.8% (3/394) of Han Chinese chromosomes from a broad population by the 1000 Genomes project (dbSNP rs189286381). Computational analyses (biochemical amino acid properties, conservation, AlignGVGD, PolyPhen2 , and SIFT) do not provide strong support for or against an impact to the protei n. While the variant?s frequency suggests that this variant is more likely benig n, it is too low to confidently rule out a disease causing role. Additional info rmation is needed to fully assess the clinical significance of the Ala8736Thr va riant. -

not provided

Benign:2

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: research

- -

May 20, 2021

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is associated with the following publications: (PMID: 27066551, 24503780, 32464347) -

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

Benign:1

Jan 31, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.42

BayesDel_addAF

Benign

-0.43

BayesDel_noAF

Benign

-0.39

CADD

Benign

DANN

Benign

0.95

Eigen

Uncertain

0.60

Eigen_PC

Pathogenic

0.68

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.86

D;D;.;D

M_CAP

Benign

0.010

MetaRNN

Benign

0.0071

T;T;T;T

MetaSVM

Benign

-1.0

PrimateAI

Uncertain

0.66

PROVEAN

Benign

-2.2

N;.;.;.

REVEL

Benign

0.18

Sift

Benign

0.28

T;.;.;.

Polyphen

0.98

.;.;D;D

Vest4

0.27

MVP

0.23

MPC

0.27

ClinPred

0.088

GERP RS

6.0

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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