rs142460433

Variant names:

• chr2-178764187-A-C
• rs142460433
• NM_001267550.2:c.10104T>G

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_Moderate BP6 BP7 BS1

The NM_001267550.2(TTN):​c.10104T>G​(p.Val3368Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000243 in 1,614,160 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0013 (1 hom., cov: 33)
  • Exomes 𝑓: 0.00013 (0 hom.)
• Consequence: TTN NM_001267550.2 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:13
• Conservation: PhyloP100: 1.04
• 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: Benign. The variant received -8 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.36).
• BP6: Variant 2-178764187-A-C is Benign according to our data. Variant chr2-178764187-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 178266.
• BP7: Synonymous conserved (PhyloP=1.04 with no splicing effect.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00131 (200/152344) while in subpopulation AFR AF = 0.00467 (194/41584). AF 95% confidence interval is 0.00413. There are 1 homozygotes in GnomAd4. There are 103 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

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.10104T>G	p.Val3368Val	synonymous	Exon 43 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.10104T>G	p.Val3368Val	synonymous	Exon 43 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133378.4		c.10104T>G	p.Val3368Val	synonymous	Exon 43 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.10104T>G	p.Val3368Val	synonymous	Exon 43 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.10104T>G	p.Val3368Val	synonymous	Exon 43 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.9828T>G	p.Val3276Val	synonymous	Exon 41 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.00131 AC: 200 AN: 152226 Hom.: 1 Cov.: 33

Gnomad AFR AF: 0.00468

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000298 AC: 75 AN: 251342 AF XY: 0.000265

Gnomad AFR exome AF: 0.00406

Gnomad AMR exome AF: 0.000116

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.000131 AC: 192 AN: 1461816 Hom.: 0 Cov.: 32 AF XY: 0.000116 AC XY: 84 AN XY: 727216

African (AFR) AF: 0.00478 AC: 160 AN: 33478

American (AMR) AF: 0.000134 AC: 6 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.0000464 AC: 4 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111948

Other (OTH) AF: 0.000364 AC: 22 AN: 60394

GnomAD4 genome AF: 0.00131 AC: 200 AN: 152344 Hom.: 1 Cov.: 33 AF XY: 0.00138 AC XY: 103 AN XY: 74502

African (AFR) AF: 0.00467 AC: 194 AN: 41584

American (AMR) AF: 0.000196 AC: 3 AN: 15308

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5184

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10628

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

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2114

Alfa AF: 0.00128 Hom.: 0

Bravo AF: 0.00138

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	-	4	not provided (4)
-	-	4	not specified (4)
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2J (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	Tibial muscular dystrophy (1)
-	-	1	TTN-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.36
CADD	Benign	9.8
DANN	Benign	0.84
PhyloP100		1.0
Mutation Taster		=75/25	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: rs142460433; hg19: chr2-179628914;