rs72646883

Positions:

• chr2-178576913-C-G

Variant summary

Our verdict is Benign. Variant got -16 ACMG points: 0P and 16B. BP4_Strong BP6_Very_Strong BS1

The NM_001267550.2(TTN):​c.69412+10G>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000351 in 1,607,940 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 Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0018 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00020 (0 hom.)
• Consequence: TTN NM_001267550.2 intron
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:11
• Conservation: PhyloP100: 0.124

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:):

ACMG classification

Verdict is Benign. Variant got -16 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BP6: Variant 2-178576913-C-G is Benign according to our data. Variant chr2-178576913-C-G is described in ClinVar as [Likely_benign]. Clinvar id is 47272.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr2-178576913-C-G is described in Lovd as [Likely_benign].
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00181 (275/152216) while in subpopulation AFR AF= 0.00599 (249/41564). AF 95% confidence interval is 0.00538. There are 0 homozygotes in gnomad4. There are 124 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TTN	NM_001267550.2	c.69412+10G>C		intron_variant		ENST00000589042.5	NP_001254479.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TTN	ENST00000589042.5	c.69412+10G>C		intron_variant		5	NM_001267550.2	ENSP00000467141.1

Frequencies

GnomAD3 genomes AF: 0.00181 AC: 275 AN: 152098 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00601

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00144

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: 0.0000294

Gnomad OTH AF: 0.000957

GnomAD3 exomes AF: 0.000458 AC: 112 AN: 244464 Hom.: 0 AF XY: 0.000392 AC XY: 52 AN XY: 132566

Gnomad AFR exome AF: 0.00599

Gnomad AMR exome AF: 0.000388

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000539

Gnomad OTH exome AF: 0.000169

GnomAD4 exome AF: 0.000199 AC: 290 AN: 1455724 Hom.: 0 Cov.: 35 AF XY: 0.000171 AC XY: 124 AN XY: 723798

Gnomad4 AFR exome AF: 0.00625

Gnomad4 AMR exome AF: 0.000505

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000188

Gnomad4 NFE exome AF: 0.0000297

Gnomad4 OTH exome AF: 0.000449

GnomAD4 genome AF: 0.00181 AC: 275 AN: 152216 Hom.: 0 Cov.: 32 AF XY: 0.00167 AC XY: 124 AN XY: 74406

Gnomad4 AFR AF: 0.00599

Gnomad4 AMR AF: 0.00144

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.000947

Alfa AF: 0.000940 Hom.: 0

Bravo AF: 0.00239

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:11

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:4

Likely benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 03, 2014	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Mar 19, 2012	c.61708+10G>C in Intron 273 of TTN: This variant is not expected to have clinica l significance because it is not located within the splice consensus sequence an d has been identified in 0.5% (17/3094) of African American chromosomes from a b road population by the NHLBI Exome Sequencing Project (http://evs.gs.washington. edu/EVS; dbSNP rs72646883). -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Jul 25, 2014	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 19, 2023	- -

TTN-related disorder Benign:1

Likely benign, no assertion criteria provided

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 04, 2019

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

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

Benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 31, 2024

- -

Cardiomyopathy Benign:1

Benign, criteria provided, single submitter

clinical testing

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Aug 11, 2016

- -

Early-onset myopathy with fatal cardiomyopathy Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Tibial muscular dystrophy Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Myopathy, myofibrillar, 9, with early respiratory failure Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Sep 10, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	8.8
DANN	Benign	0.77

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: rs72646883; hg19: chr2-179441640;