Our verdict is Likely benign. Variant got -1 ACMG points: 1P and 2B. PP2BP4BP6
The NM_001267550.2(TTN):c.50597G>A(p.Arg16866Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,612,954 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R16866R) has been classified 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]
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]
Verdict is Likely_benign. Variant got -1 ACMG points.
PP2
Missense variant where missense usually causes diseases, TTN
BP4
Computational evidence support a benign effect (MetaRNN=0.2652624).
BP6
Variant 2-178611632-C-T is Benign according to our data. Variant chr2-178611632-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 467225.We mark this variant Likely_benign, oryginal submissions are: {Benign=2, Uncertain_significance=4}.
Uncertain significance, no assertion criteria provided
clinical testing
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
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Uncertain significance, no assertion criteria provided
clinical testing
Clinical Genetics, Academic Medical Center
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Uncertain significance, no assertion criteria provided
clinical testing
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
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Autosomal recessive limb-girdle muscular dystrophy type 2J Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
Apr 28, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Autosomal recessive limb-girdle muscular dystrophy type 2J;C1858763:Dilated cardiomyopathy 1G Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Invitae
Jun 19, 2017
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Dilated cardiomyopathy 1G Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
Apr 28, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Early-onset myopathy with fatal cardiomyopathy Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
Apr 28, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Tibial muscular dystrophy Benign:1
Benign, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
May 08, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -
Myopathy, myofibrillar, 9, with early respiratory failure Benign:1
Benign, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
May 08, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign. -