rs1419714561

Variant names:

• chr2-178584308-G-A
• rs1419714561
• NM_001267550.2:c.65243C>T

Your query was ambiguous. Multiple possible variants found:

• chr2-178584308-G-A
• chr2-178584308-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_001267550.2(TTN):​c.65243C>T​(p.Pro21748Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000277 in 1,443,180 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 11/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.21

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.27163953).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2	c.65243C>T	p.Pro21748Leu	missense_variant	Exon 311 of 363	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.65243C>T	p.Pro21748Leu	missense_variant	Exon 311 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000418 AC: 1 AN: 239274 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 129830

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000299

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000277 AC: 4 AN: 1443180 Hom.: 0 Cov.: 32 AF XY: 0.00000140 AC XY: 1 AN XY: 714942

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000920

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Mar 02, 2017

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Pro19180Leu variant in TTN has not been previously reported in individuals with cardiomyopathy. It has been identified in 1/32626 Latino chromosomes by th e Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org). Compu tational prediction tools and conservation analysis suggest that this variant ma y impact the protein, though this information is not predictive enough to determ ine pathogenicity. In summary, the clinical significance of the p.Pro19180Leu va riant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Benign	-0.094	T
BayesDel_noAF	Benign	-0.28
CADD	Benign	22
DANN	Benign	0.93
Eigen	Pathogenic	0.77
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.93	D;D;D;.;D;D;D
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.27	T;T;T;T;T;T;T
MetaSVM	Benign	-0.49	T
MutationAssessor	Benign	0.78	.;.;.;N;.;.;N
PrimateAI	Uncertain	0.62	T
PROVEAN	Pathogenic	-6.1	D;D;.;.;D;D;.
REVEL	Uncertain	0.29
Sift	Uncertain	0.013	D;T;.;.;T;T;.
Polyphen		0.99	.;.;.;D;.;.;D
Vest4		0.33
MutPred		0.28		.;.;.;Loss of disorder (P = 0.0191);.;.;Loss of disorder (P = 0.0191);
MVP		0.47
MPC		0.34
ClinPred		0.27	T
GERP RS		6.0

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: rs1419714561; hg19: chr2-179449035;