NM_001267550.2:c.58958G>A

Variant names:

• chr2-178593250-C-T
• rs1398360418
• NM_001267550.2:c.58958G>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BP4

The NM_001267550.2(TTN):​c.58958G>A​(p.Arg19653Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,180 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 (★★). Synonymous variant affecting the same amino acid position (i.e. R19653R) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.86
• Publications: 2 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 -1 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.34186232).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001267550.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	NM_001267550.2	MANE Select	c.58958G>A	p.Arg19653Gln	missense	Exon 299 of 363	NP_001254479.2
	TTN	NM_001256850.1		c.54035G>A	p.Arg18012Gln	missense	Exon 249 of 313	NP_001243779.1
	TTN	NM_133378.4		c.51254G>A	p.Arg17085Gln	missense	Exon 248 of 312	NP_596869.4

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	ENST00000589042.5	TSL:5 MANE Select	c.58958G>A	p.Arg19653Gln	missense	Exon 299 of 363	ENSP00000467141.1
	TTN	ENST00000446966.2	TSL:1	c.58802G>A	p.Arg19601Gln	missense	Exon 297 of 361	ENSP00000408004.2
	TTN	ENST00000436599.2	TSL:1	c.58682G>A	p.Arg19561Gln	missense	Exon 297 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151964 Hom.: 0 Cov.: 32

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: 0.000208

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000805 AC: 2 AN: 248412 AF XY: 0.00000742

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000290

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000342 AC: 5 AN: 1461216 Hom.: 0 Cov.: 35 AF XY: 0.00000275 AC XY: 2 AN XY: 726900

African (AFR) AF: 0.00 AC: 0 AN: 33450

American (AMR) AF: 0.0000224 AC: 1 AN: 44692

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26116

East Asian (EAS) AF: 0.00 AC: 0 AN: 39616

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86230

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111604

Other (OTH) AF: 0.00 AC: 0 AN: 60350

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151964 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74200

African (AFR) AF: 0.00 AC: 0 AN: 41402

American (AMR) AF: 0.00 AC: 0 AN: 15240

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5140

South Asian (SAS) AF: 0.000208 AC: 1 AN: 4818

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67964

Other (OTH) AF: 0.00 AC: 0 AN: 2090

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.36
BayesDel_addAF	Benign	0.0042	T
BayesDel_noAF	Benign	-0.13
CADD	Uncertain	24
DANN	Benign	0.97
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Benign	0.018	T
MetaRNN	Benign	0.34	T
MetaSVM	Uncertain	0.040	D
MutationAssessor	Pathogenic	3.2	M
PhyloP100		7.9
PrimateAI	Uncertain	0.52	T
PROVEAN	Uncertain	-3.3	D
REVEL	Uncertain	0.47
Sift	Uncertain	0.0030	D
Polyphen		1.0	D
Vest4		0.43
MutPred		0.69		Loss of phosphorylation at S18014 (P = 0.0836)
MVP		0.37
MPC		0.50
ClinPred		0.68	D
GERP RS		6.2
Mutation Taster		=95/5	polymorphism

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

Other links and lift over

dbSNP: rs1398360418; hg19: chr2-179457977; COSMIC: COSV60273725; COSMIC: COSV60273725;