NM_001267550.2:c.57559G>A

Variant names:

• chr2-178595795-C-T
• rs764203267
• NM_001267550.2:c.57559G>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.57559G>A​(p.Val19187Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00002 in 1,602,020 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V19187A) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000072 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:9
• Conservation: PhyloP100: 6.13
• 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=0.17872581).

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	NM_001267550.2	MANE Select	c.57559G>A	p.Val19187Ile	missense	Exon 295 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.52636G>A	p.Val17546Ile	missense	Exon 245 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.49855G>A	p.Val16619Ile	missense	Exon 244 of 312	NP_596869.4	Q8WZ42-11

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	ENST00000589042.5	TSL:5 MANE Select	c.57559G>A	p.Val19187Ile	missense	Exon 295 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.57403G>A	p.Val19135Ile	missense	Exon 293 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.57283G>A	p.Val19095Ile	missense	Exon 293 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.0000724 AC: 11 AN: 151940 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000121

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000393

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: 0.00

GnomAD2 exomes AF: 0.0000263 AC: 6 AN: 228392 AF XY: 0.0000326

Gnomad AFR exome AF: 0.0000712

Gnomad AMR exome AF: 0.0000929

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000978

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000145 AC: 21 AN: 1450080 Hom.: 0 Cov.: 34 AF XY: 0.0000167 AC XY: 12 AN XY: 719944

African (AFR) AF: 0.0000300 AC: 1 AN: 33302

American (AMR) AF: 0.0000928 AC: 4 AN: 43120

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25870

East Asian (EAS) AF: 0.00 AC: 0 AN: 39136

South Asian (SAS) AF: 0.0000358 AC: 3 AN: 83696

European-Finnish (FIN) AF: 0.0000189 AC: 1 AN: 52908

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5740

European-Non Finnish (NFE) AF: 0.00000814 AC: 9 AN: 1106318

Other (OTH) AF: 0.0000500 AC: 3 AN: 59990

GnomAD4 genome AF: 0.0000724 AC: 11 AN: 151940 Hom.: 0 Cov.: 32 AF XY: 0.000108 AC XY: 8 AN XY: 74198

African (AFR) AF: 0.000121 AC: 5 AN: 41372

American (AMR) AF: 0.000393 AC: 6 AN: 15252

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5152

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10582

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67972

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

Alfa AF: 0.0000282 Hom.: 0

Bravo AF: 0.0000718

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000259 AC: 1

ExAC AF: 0.0000166 AC: 2

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J (1)
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1838244:Tibial muscular dystrophy;C1858763:Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9;C1863599:Myopathy, myofibrillar, 9, with early respiratory failure;C2673677:Early-onset myopathy with fatal cardiomyopathy (1)
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
-	1	-	Cardiovascular phenotype (1)
-	1	-	Dilated cardiomyopathy 1G (1)
-	1	-	Early-onset myopathy with fatal cardiomyopathy (1)
-	1	-	Myopathy, myofibrillar, 9, with early respiratory failure (1)
-	1	-	not provided (1)
-	1	-	Tibial muscular dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.43
CADD	Benign	22
DANN	Uncertain	0.98
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.88	D
M_CAP	Benign	0.022	T
MetaRNN	Benign	0.18	T
MetaSVM	Benign	-0.79	T
MutationAssessor	Benign	1.6	L
PhyloP100		6.1
PrimateAI	Benign	0.45	T
PROVEAN	Benign	-0.69	N
REVEL	Benign	0.23
Sift	Benign	0.12	T
Polyphen		0.95	P
Vest4		0.33
MutPred		0.66		Gain of catalytic residue at L17551 (P = 0.0248)
MVP		0.39
MPC		0.11
ClinPred		0.28	T
GERP RS		6.0
Mutation Taster		=79/21	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: rs764203267; hg19: chr2-179460522; COSMIC: COSV105217086; COSMIC: COSV105217086;