rs900082928

Variant names:

• chr2-178594051-T-C
• rs900082928
• NM_001267550.2:c.58342A>G

Variant summary

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

The NM_001267550.2(TTN):​c.58342A>G​(p.Lys19448Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,432 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 (★★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.96
• 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 -1 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.3448204).

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.58342A>G	p.Lys19448Glu	missense	Exon 297 of 363	NP_001254479.2
	TTN	NM_001256850.1		c.53419A>G	p.Lys17807Glu	missense	Exon 247 of 313	NP_001243779.1
	TTN	NM_133378.4		c.50638A>G	p.Lys16880Glu	missense	Exon 246 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.58342A>G	p.Lys19448Glu	missense	Exon 297 of 363	ENSP00000467141.1
	TTN	ENST00000446966.2	TSL:1	c.58186A>G	p.Lys19396Glu	missense	Exon 295 of 361	ENSP00000408004.2
	TTN	ENST00000436599.2	TSL:1	c.58066A>G	p.Lys19356Glu	missense	Exon 295 of 361	ENSP00000405517.2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152098 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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

GnomAD2 exomes AF: 0.00000403 AC: 1 AN: 248430 AF XY: 0.00

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: 0.00000411 AC: 6 AN: 1461334 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 726946

African (AFR) AF: 0.00 AC: 0 AN: 33464

American (AMR) AF: 0.0000224 AC: 1 AN: 44694

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39618

South Asian (SAS) AF: 0.00 AC: 0 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111666

Other (OTH) AF: 0.00 AC: 0 AN: 60354

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152098 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74292

African (AFR) AF: 0.00 AC: 0 AN: 41458

American (AMR) AF: 0.000131 AC: 2 AN: 15260

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5158

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67984

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

Alfa AF: 0.0000565 Hom.: 0

Bravo AF: 0.0000302

EpiCase AF: 0.0000546

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Aug 28, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Dilated cardiomyopathy 1G;C1861065:Hypertrophic cardiomyopathy 9 Uncertain:1

Aug 11, 2021

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ACMG classification criteria: BP4 supporting

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.32
CADD	Benign	22
DANN	Benign	0.93
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.81	T
M_CAP	Benign	0.013	T
MetaRNN	Benign	0.34	T
MetaSVM	Benign	-0.69	T
MutationAssessor	Benign	1.7	L
PhyloP100		8.0
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.0	D
REVEL	Uncertain	0.34
Sift	Benign	0.11	T
Polyphen		1.0	D
Vest4		0.49
MutPred		0.47		Gain of ubiquitination at K17809 (P = 0.0204)
MVP		0.24
MPC		0.54
ClinPred		0.24	T
GERP RS		6.2
Mutation Taster		=86/14	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: rs900082928; hg19: chr2-179458778;