NM_001267550.2:c.16118C>A

Variant names:

• chr2-178733058-G-T
• rs1057103177
• NM_001267550.2:c.16118C>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001267550.2(TTN):​c.16118C>A​(p.Thr5373Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,612,480 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.967
• Publications: 0 publications found

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

Our verdict: Likely_benign. The variant received -2 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.1714735).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2	c.16118C>A	p.Thr5373Asn	missense_variant	Exon 55 of 363	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.16118C>A	p.Thr5373Asn	missense_variant	Exon 55 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152150 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.00

Gnomad OTH AF: 0.000478

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460330 Hom.: 0 Cov.: 36 AF XY: 0.00000275 AC XY: 2 AN XY: 726314

African (AFR) AF: 0.0000299 AC: 1 AN: 33452

American (AMR) AF: 0.00 AC: 0 AN: 44612

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26046

East Asian (EAS) AF: 0.00 AC: 0 AN: 39566

South Asian (SAS) AF: 0.00 AC: 0 AN: 86084

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53348

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5754

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111154

Other (OTH) AF: 0.00 AC: 0 AN: 60314

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152150 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74332

African (AFR) AF: 0.0000483 AC: 2 AN: 41440

American (AMR) AF: 0.0000655 AC: 1 AN: 15276

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.000478 AC: 1 AN: 2090

Alfa AF: 0.000142 Hom.: 0

Bravo AF: 0.0000567

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Dec 27, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.27	T
BayesDel_noAF	Benign	-0.63
CADD	Benign	17
DANN	Benign	0.88
Eigen	Benign	-0.49
Eigen_PC	Benign	-0.36
FATHMM_MKL	Benign	0.27	N
LIST_S2	Benign	0.59	T;T;.;T
M_CAP	Benign	0.0061	T
MetaRNN	Benign	0.17	T;T;T;T
MetaSVM	Benign	-1.1	T
PhyloP100		0.97
PrimateAI	Benign	0.32	T
PROVEAN	Benign	-1.9	N;.;.;.
REVEL	Benign	0.086
Sift	Benign	0.39	T;.;.;.
Polyphen		0.0	.;.;B;B
Vest4		0.35
MutPred		0.54		.;.;Loss of MoRF binding (P = 0.2692);Loss of MoRF binding (P = 0.2692);
MVP		0.20
MPC		0.095
ClinPred		0.11	T
GERP RS		2.5
Mutation Taster		=90/10	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1057103177; hg19: chr2-179597785;