rs563954136

Variant names:

• chr2-178712199-A-G
• rs563954136
• NM_001267550.2:c.27631T>C

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_Strong BP6 BP7

The NM_001267550.2(TTN):​c.27631T>C​(p.Leu9211Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000013 in 1,613,416 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: TTN NM_001267550.2 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: 0.496
• 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]

LOC124906100 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -6 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).
• BP6: Variant 2-178712199-A-G is Benign according to our data. Variant chr2-178712199-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 466963.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].
• BP7: Synonymous conserved (PhyloP=0.496 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TTN	NM_001267550.2	c.27631T>C	p.Leu9211Leu	synonymous_variant	Exon 96 of 363	ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.27631T>C	p.Leu9211Leu	synonymous_variant	Exon 96 of 363	5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes AF: 0.0000526 AC: 8 AN: 152160 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.000193

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.00

GnomAD2 exomes AF: 0.0000201 AC: 5 AN: 248202 AF XY: 0.0000223

Gnomad AFR exome AF: 0.000129

Gnomad AMR exome AF: 0.0000581

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: 0.00000890 AC: 13 AN: 1461138 Hom.: 0 Cov.: 32 AF XY: 0.0000110 AC XY: 8 AN XY: 726768

African (AFR) AF: 0.000239 AC: 8 AN: 33454

American (AMR) AF: 0.0000447 AC: 2 AN: 44696

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26106

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86194

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

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111492

Other (OTH) AF: 0.0000166 AC: 1 AN: 60354

GnomAD4 genome AF: 0.0000525 AC: 8 AN: 152278 Hom.: 0 Cov.: 33 AF XY: 0.0000403 AC XY: 3 AN XY: 74440

African (AFR) AF: 0.000192 AC: 8 AN: 41576

American (AMR) AF: 0.00 AC: 0 AN: 15276

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

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

South Asian (SAS) AF: 0.00 AC: 0 AN: 4818

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68026

Other (OTH) AF: 0.00 AC: 0 AN: 2116

Alfa AF: 0.0000329 Hom.: 0

Bravo AF: 0.0000529

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:1

Oct 08, 2020

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 11, 2018

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not specified Benign:1

Feb 07, 2022

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: TTN c.23899T>C alters a non-conserved nucleotide resulting in a synonymous change. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 2e-05 in 248202 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.23899T>C in individuals affected with Dilated Cardiomyopathy/Limb Girle Muscular Dystrophy/TTN-related disorders and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (Likely Benign, n=2, VUS, n=1). Based on the evidence outlined above, the variant was classified as likely benign. -

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

Nov 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	0.71
DANN	Benign	0.44
PhyloP100		0.50
Mutation Taster		=98/2	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: rs563954136; hg19: chr2-179576926;