NM_001267550.2:c.11312-5130T>G

Variant names:

• chr2-178747051-A-C
• rs201308378
• NM_001267550.2:c.11312-5130T>G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Strong

The NM_001267550.2(TTN):​c.11312-5130T>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000657 in 1,613,192 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000059 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000066 (1 hom.)
• Consequence: TTN NM_001267550.2 intron
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.796
• Publications: 1 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 -4 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.06430325).

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.11312-5130T>G		intron	N/A	NP_001254479.2
	TTN	NM_133379.5		c.15349T>G	p.Tyr5117Asp	missense	Exon 46 of 46	NP_596870.2
	TTN	NM_001256850.1		c.10361-5130T>G		intron	N/A	NP_001243779.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	ENST00000589042.5	TSL:5 MANE Select	c.11312-5130T>G		intron	N/A	ENSP00000467141.1
	TTN	ENST00000446966.2	TSL:1	c.11312-5130T>G		intron	N/A	ENSP00000408004.2
	TTN	ENST00000436599.2	TSL:1	c.11036-5130T>G		intron	N/A	ENSP00000405517.2

Frequencies

GnomAD3 genomes AF: 0.0000593 AC: 9 AN: 151816 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000242

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000657

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: 0.0000883

Gnomad OTH AF: 0.000480

GnomAD2 exomes AF: 0.000104 AC: 26 AN: 250364 AF XY: 0.000126

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000261

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000141

Gnomad OTH exome AF: 0.000164

GnomAD4 exome AF: 0.0000664 AC: 97 AN: 1461258 Hom.: 1 Cov.: 34 AF XY: 0.0000757 AC XY: 55 AN XY: 726928

African (AFR) AF: 0.00 AC: 0 AN: 33438

American (AMR) AF: 0.000224 AC: 10 AN: 44650

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26084

East Asian (EAS) AF: 0.00 AC: 0 AN: 39672

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86228

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53368

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

European-Non Finnish (NFE) AF: 0.0000747 AC: 83 AN: 1111694

Other (OTH) AF: 0.0000497 AC: 3 AN: 60364

GnomAD4 genome AF: 0.0000592 AC: 9 AN: 151934 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74250

African (AFR) AF: 0.0000241 AC: 1 AN: 41452

American (AMR) AF: 0.0000656 AC: 1 AN: 15236

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3464

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10596

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000883 AC: 6 AN: 67912

Other (OTH) AF: 0.000475 AC: 1 AN: 2106

Alfa AF: 0.000134 Hom.: 0

Bravo AF: 0.0000756

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.0000741 AC: 9

EpiCase AF: 0.000164

EpiControl AF: 0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Oct 12, 2015

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Missense variants in the TTN gene are considered 'unclassified' if they are not previously reported in the literature and do not have >1% frequency in the population to be considered a polymorphism. Research indicates that truncating mutations in the TTN gene are expected to account for approximately 25% of familial and 18% of sporadic idiopathic DCM; however, truncating variants in the TTN gene have been reported in approximately 3% of reported control alleles. There has been little investigation into non-truncating variants. (Herman D et al. Truncations of titin causing dilated cardiomyopathy. N Eng J Med 366:619-628, 2012) The variant is found in DCM-CRDM panel(s).

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 Uncertain:1

Sep 13, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Uncertain:1

Jun 24, 2013

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: research

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.49	T
BayesDel_noAF	Benign	-0.64
CADD	Benign	8.3
DANN	Uncertain	0.97
Eigen	Benign	-0.57
Eigen_PC	Benign	-0.51
FATHMM_MKL	Benign	0.12	N
LIST_S2	Benign	0.27	T
M_CAP	Benign	0.0089	T
MetaRNN	Benign	0.064	T
MetaSVM	Benign	-0.97	T
PhyloP100		0.80
PROVEAN	Benign	0.14	N
REVEL	Benign	0.070
Sift	Uncertain	0.0010	D
Sift4G	Benign	0.21	T
Polyphen		0.0010	B
Vest4		0.27
MVP		0.40
ClinPred		0.074	T
GERP RS		3.9
Mutation Taster		=94/6	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: rs201308378; hg19: chr2-179611778;