Our verdict is Benign. Variant got -16 ACMG points: 0P and 16B. BP4_StrongBP6_Very_StrongBS2
The NM_001267550.2(TTN):c.96904+8C>T variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000115 in 1,532,890 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).
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]
Computational evidence support a benign effect (BayesDel_noAF=-0.85).
BP6
Variant 2-178543061-G-A is Benign according to our data. Variant chr2-178543061-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 165698.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
Likely benign, criteria provided, single submitter
clinical testing
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Jul 01, 2014
89200+8C>T in intron 296 of TTN: This variant is not expected to have clinical s ignificance because it does not diverge from the splice site consensus sequence and computational tools do not predict an impact to splicing. -
Autosomal recessive limb-girdle muscular dystrophy type 2J Benign:1
Benign, criteria provided, single submitter
clinical testing
Genome-Nilou Lab
Sep 10, 2021
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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 27, 2024
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Early-onset myopathy with fatal cardiomyopathy Benign:1
Benign, criteria provided, single submitter
clinical testing
Genome-Nilou Lab
Sep 10, 2021
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Tibial muscular dystrophy Benign:1
Benign, criteria provided, single submitter
clinical testing
Genome-Nilou Lab
Sep 10, 2021
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Myopathy, myofibrillar, 9, with early respiratory failure Benign:1