rs397517825

Variant names:

• chr2-178741727-C-T
• rs397517825
• NM_001267550.2:c.11506G>A

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_Strong BP6 BS1 BS2

The NM_001267550.2(TTN):​c.11506G>A​(p.Val3836Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000408 in 1,613,740 control chromosomes in the GnomAD database, including 11 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V3836A) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.00020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00043 (11 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:10
• Conservation: PhyloP100: 2.98
• 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 -13 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.006786436).
• BP6: Variant 2-178741727-C-T is Benign according to our data. Variant chr2-178741727-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 47809.
• BS1: Variant frequency is greater than expected in population sas. GnomAd4 allele frequency = 0.000204 (31/152294) while in subpopulation SAS AF = 0.00622 (30/4822). AF 95% confidence interval is 0.00448. There are 0 homozygotes in GnomAd4. There are 22 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
• BS2: High Homozygotes in GnomAdExome4 at 11 AD,AR gene

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.11506G>A	p.Val3836Met	missense	Exon 48 of 363	NP_001254479.2	Q8WZ42-12
	TTN	NM_001256850.1		c.10555G>A	p.Val3519Met	missense	Exon 46 of 313	NP_001243779.1	Q8WZ42-1
	TTN	NM_133437.4		c.10993G>A	p.Val3665Met	missense	Exon 46 of 192	NP_597681.4	A0A0A0MRA3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TTN	ENST00000589042.5	TSL:5 MANE Select	c.11506G>A	p.Val3836Met	missense	Exon 48 of 363	ENSP00000467141.1	Q8WZ42-12
	TTN	ENST00000446966.2	TSL:1	c.11506G>A	p.Val3836Met	missense	Exon 48 of 361	ENSP00000408004.2	A0A1B0GXE3
	TTN	ENST00000436599.2	TSL:1	c.11230G>A	p.Val3744Met	missense	Exon 46 of 361	ENSP00000405517.2	A0A0C4DG59

Frequencies

GnomAD3 genomes AF: 0.000204 AC: 31 AN: 152176 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: 0.00622

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.000953 AC: 237 AN: 248586 AF XY: 0.00124

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000622

Gnomad OTH exome AF: 0.000331

GnomAD4 exome AF: 0.000429 AC: 627 AN: 1461446 Hom.: 11 Cov.: 32 AF XY: 0.000649 AC XY: 472 AN XY: 726994

African (AFR) AF: 0.00 AC: 0 AN: 33468

American (AMR) AF: 0.00 AC: 0 AN: 44700

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39662

South Asian (SAS) AF: 0.00678 AC: 585 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53388

Middle Eastern (MID) AF: 0.000173 AC: 1 AN: 5766

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1111726

Other (OTH) AF: 0.000580 AC: 35 AN: 60358

GnomAD4 genome AF: 0.000204 AC: 31 AN: 152294 Hom.: 0 Cov.: 32 AF XY: 0.000295 AC XY: 22 AN XY: 74454

African (AFR) AF: 0.00 AC: 0 AN: 41580

American (AMR) AF: 0.00 AC: 0 AN: 15284

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5176

South Asian (SAS) AF: 0.00622 AC: 30 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68018

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

Alfa AF: 0.0000317 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.00100 AC: 121

Asia WGS AF: 0.00549 AC: 19 AN: 3478

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	3	not specified (4)
-	-	3	not provided (3)
-	-	1	Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G (1)
-	-	1	Cardiomyopathy (1)
-	-	1	Cardiovascular phenotype (1)
-	-	1	TTN-related disorder (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Benign	-0.48	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	20
DANN	Benign	0.93
Eigen	Uncertain	0.47
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Benign	0.83	T
M_CAP	Benign	0.019	T
MetaRNN	Benign	0.0068	T
MetaSVM	Benign	-0.94	T
PhyloP100		3.0
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-1.3	N
REVEL	Benign	0.12
Sift	Benign	0.14	T
Vest4		0.55
MVP		0.41
MPC		0.29
ClinPred		0.10	T
GERP RS		6.1
Mutation Taster		=77/23	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: rs397517825; hg19: chr2-179606454;