rs140914855

chr2-178776282-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP2 BP4

The NM_001267550.2(TTN):c.5582G>A(p.Arg1861His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000799 in 1,614,050 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1861C) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000085 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:8 B:1 O:1
• Conservation: PhyloP100: 7.88

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-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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PP2: Missense variant where missense usually causes diseases, TTN
• BP4: Computational evidence support a benign effect (MetaRNN=0.35122758).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TTN	NM_001267550.2	c.5582G>A	p.Arg1861His	missense_variant	28/363	ENST00000589042.5
TTN	NM_133379.5	c.5582G>A	p.Arg1861His	missense_variant	28/46	ENST00000360870.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TTN	ENST00000589042.5	c.5582G>A	p.Arg1861His	missense_variant	28/363	5	NM_001267550.2	P1
TTN	ENST00000360870.10	c.5582G>A	p.Arg1861His	missense_variant	28/46	5	NM_133379.5
TTN-AS1	ENST00000659121.1	n.3709C>T		non_coding_transcript_exon_variant	12/13

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152170 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000915 AC: 23 AN: 251272 Hom.: 0 AF XY: 0.000118 AC XY: 16 AN XY: 135790

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000150

Gnomad OTH exome AF: 0.000489

GnomAD4 exome AF: 0.0000848 AC: 124 AN: 1461762 Hom.: 0 Cov.: 33 AF XY: 0.0000894 AC XY: 65 AN XY: 727194

Gnomad4 AFR exome AF: 0.000269

Gnomad4 AMR exome AF: 0.000112

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000504

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000917

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000328 AC: 5 AN: 152288 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74464

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.000288

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000111 Hom.: 0

Bravo AF: 0.0000378

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.0000824 AC: 10

Asia WGS AF: 0.000289 AC: 1 AN: 3476

EpiCase AF: 0.000109

EpiControl AF: 0.000237

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:8 Benign:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:3 Benign:1 Other:1

Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Sep 01, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Oct 16, 2015	- -
not provided, no classification provided	phenotyping only	GenomeConnect, ClinGen	-	Variant interpretted as Uncertain significance and reported on 07-22-2019 by Lab or GTR ID Credit Valley Hospital Department of Laboratory Medicine. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 21, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Mar 28, 2019	- -

not specified Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Sep 12, 2016	The p.Arg1861His variant in TTN has been identified by our laboratory in 1 indiv idual with DCM and 1 individual with LVNC. This variant has been identified in 9 /66738 European chromosomes by the Exome Aggregation Consortium (ExAC, http://ex ac.broadinstitute.org; dbSNP rs140914855). Computational prediction tools and co nservation analysis do not provide strong support for or against an impact to th e protein. In summary, the clinical significance of the p.Arg1861His variant is uncertain. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Jan 08, 2015	- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 17, 2017

- -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Jul 02, 2019

- -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 25, 2020

The p.R1815H variant (also known as c.5444G>A), located in coding exon 26 of the TTN gene, results from a G to A substitution at nucleotide position 5444. The arginine at codon 1815 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.47
BayesDel_addAF	Benign	-0.021	T
BayesDel_noAF	Uncertain	-0.010
Cadd	Pathogenic	26
Dann	Benign	0.97
Eigen	Pathogenic	0.70
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.95	D;D;D;.;D;D;D;D
M_CAP	Benign	0.037	D
MetaRNN	Benign	0.35	T;T;T;T;T;T;T;T
MetaSVM	Uncertain	-0.21	T
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Uncertain	-3.3	D;D;.;.;D;D;.;D
REVEL	Uncertain	0.55
Sift	Benign	0.092	T;T;.;.;D;D;.;D
Polyphen		1.0	.;.;.;D;.;.;D;D
Vest4		0.35
MVP		0.50
MPC		0.52
ClinPred		0.13	T
GERP RS		5.2

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

Other links and lift over

dbSNP: rs140914855; hg19: chr2-179641009; COSMIC: COSV59994935; COSMIC: COSV59994935;