rs572691153

Positions:

• chr2-178776009-T-C

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 1P and 3B. PP2 BP4_Moderate BP6

The NM_001267550.2(TTN):​c.5855A>G​(p.His1952Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000229 in 1,614,202 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000024 (0 hom.)
• Consequence: TTN NM_001267550.2 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 4.22

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

Verdict is Likely_benign. Variant got -2 ACMG points.

• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), TTN. . Gene score misZ -1.1021 (greater than the threshold 3.09). Trascript score misZ 6.9794 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, tibial muscular dystrophy, early-onset myopathy with fatal cardiomyopathy, autosomal recessive centronuclear myopathy, hypertrophic cardiomyopathy, hypertrophic cardiomyopathy 9, TTN-related myopathy, dilated cardiomyopathy 1G, arrhythmogenic right ventricular cardiomyopathy, myopathy, myofibrillar, 9, with early respiratory failure, familial isolated dilated cardiomyopathy, childhood-onset progressive contractures-limb-girdle weakness-muscle dystrophy syndrome, autosomal recessive limb-girdle muscular dystrophy type 2J.
• BP4: Computational evidence support a benign effect (MetaRNN=0.10926488).
• BP6: Variant 2-178776009-T-C is Benign according to our data. Variant chr2-178776009-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 192078.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2	c.5855A>G	p.His1952Arg	missense_variant	28/363	ENST00000589042.5	NP_001254479.2
TTN	NM_133379.5	c.5855A>G	p.His1952Arg	missense_variant	28/46	ENST00000360870.10	NP_596870.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.5855A>G	p.His1952Arg	missense_variant	28/363	5	NM_001267550.2	ENSP00000467141	P1
TTN	ENST00000360870.10	c.5855A>G	p.His1952Arg	missense_variant	28/46	5	NM_133379.5	ENSP00000354117
TTN-AS1	ENST00000659121.1	n.3436T>C		non_coding_transcript_exon_variant	12/13

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152234 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: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000279 AC: 7 AN: 251192 Hom.: 0 AF XY: 0.0000368 AC XY: 5 AN XY: 135742

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 SAS exome AF: 0.000196

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000239 AC: 35 AN: 1461850 Hom.: 0 Cov.: 33 AF XY: 0.0000303 AC XY: 22 AN XY: 727232

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000359

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152352 Hom.: 0 Cov.: 32 AF XY: 0.0000268 AC XY: 2 AN XY: 74498

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000415

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.0000330 AC: 4

Asia WGS AF: 0.000289 AC: 1 AN: 3476

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Feb 18, 2021	- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 05, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.080
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.13
CADD	Benign	19
DANN	Benign	0.84
Eigen	Benign	-0.13
Eigen_PC	Benign	-0.026
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.85	T;T;T;.;T;T;D;T
M_CAP	Benign	0.024	T
MetaRNN	Benign	0.11	T;T;T;T;T;T;T;T
MetaSVM	Benign	-0.98	T
MutationTaster	Benign	1.0	N;N;N;N;N;N;N
PrimateAI	Uncertain	0.49	T
PROVEAN	Uncertain	-3.7	D;D;.;.;D;D;.;D
REVEL	Benign	0.21
Sift	Benign	0.43	T;T;.;.;T;T;.;T
Sift4G	Benign	0.34	.;.;.;.;.;.;.;T
Polyphen		0.45, 0.90	.;.;.;P;.;.;P;P
Vest4		0.40
MutPred		0.22		Gain of MoRF binding (P = 0.1009);.;Gain of MoRF binding (P = 0.1009);Gain of MoRF binding (P = 0.1009);.;.;Gain of MoRF binding (P = 0.1009);Gain of MoRF binding (P = 0.1009);
MVP		0.22
MPC		0.12
ClinPred		0.12	T
GERP RS		5.1

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

Publications

LitVar

Other links and lift over

dbSNP: rs572691153; hg19: chr2-179640736;