Submissions for variant NM_001267550.2(TTN):c.69864A>G (p.Ile23288Met)

gnomAD frequency: 0.00026  dbSNP: rs368867993

Total submissions: 14

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	RCV000152233	SCV000201029	uncertain significance	not specified	2016-05-06	criteria provided, single submitter	clinical testing	Variant classified as Uncertain Significance - Favor Benign. The p.Ile20720Met v ariant in TTN has been identified by our laboratory in 1 Hispanic individual wit h LVNC and Ebstein's anomaly and 1 individual with neonatal onset cardiomyopathy . However, the individual with neonatal onset cardiomyopathy carried 2 pathogeni c variants in another gene that were sufficient to explain their disease. This v ariant has also been identified in 0.1% (10/9520) of African chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs3688 67993). Computational prediction tools and conservation analysis suggest that th e variant may not impact the protein, though this information is not predictive enough to rule out pathogenicity. In summary, while the clinical significance of the p.Ile20720Met variant is uncertain, these data suggest that it is more like ly to be benign.
Eurofins Ntd Llc (ga)	RCV000723936	SCV000203696	uncertain significance	not provided	2018-09-11	criteria provided, single submitter	clinical testing
Invitae	RCV001081781	SCV000643592	likely benign	Dilated cardiomyopathy 1G; Autosomal recessive limb-girdle muscular dystrophy type 2J	2024-01-29	criteria provided, single submitter	clinical testing
GeneDx	RCV000723936	SCV000730899	likely benign	not provided	2020-11-27	criteria provided, single submitter	clinical testing
Illumina Laboratory Services, Illumina	RCV001130195	SCV001289765	benign	Tibial muscular dystrophy	2018-01-13	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease.
Illumina Laboratory Services, Illumina	RCV001130196	SCV001289766	uncertain significance	Dilated cardiomyopathy 1G	2018-01-13	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Illumina Laboratory Services, Illumina	RCV001130896	SCV001290491	benign	Myopathy, myofibrillar, 9, with early respiratory failure	2018-01-13	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease.
Illumina Laboratory Services, Illumina	RCV001130897	SCV001290492	uncertain significance	Autosomal recessive limb-girdle muscular dystrophy type 2J	2018-01-13	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Illumina Laboratory Services, Illumina	RCV001130898	SCV001290493	uncertain significance	Early-onset myopathy with fatal cardiomyopathy	2018-01-13	criteria provided, single submitter	clinical testing	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease.
Baylor Genetics	RCV001130897	SCV001521949	uncertain significance	Autosomal recessive limb-girdle muscular dystrophy type 2J	2020-09-30	criteria provided, single submitter	clinical testing	This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868].
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	RCV000723936	SCV002047902	uncertain significance	not provided	2021-02-04	criteria provided, single submitter	clinical testing	The TTN c.69864A>G; p.Ile23288Met variant (rs368867993; ClinVar Variation ID: 165861) is rare in the general population (<0.2% allele frequency in the Genome Aggregation Database) and has not been reported in the medical literature in association with dilated cardiomyopathy (DCM) or other TTN-related disease. The clinical relevance of rare missense variants in this gene, which are identified on average once per individual sequenced in affected populations (Herman 2012), is not well understood. Yet, evidence suggests that the vast majority of such missense variants do not contribute to the clinical outcome of DCM (Begay 2015). Thus, the clinical significance of the p.Ile23288Met variant cannot be determined with certainty. References: Begay RL et al. Role of Titin Missense Variants in Dilated Cardiomyopathy. J Am Heart Assoc. 2015 Nov 13;4(11). Herman DS et al. Truncations of titin causing dilated cardiomyopathy. N Engl J Med. 2012 Feb 16;366(7):619-28. Linke WA and Hamdani N. Gigantic business: titin properties and function through thick and thin. Circ Res 2014; 114(6): 1052-1068.
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV000152233	SCV002600421	likely benign	not specified	2022-10-10	criteria provided, single submitter	clinical testing	Variant summary: TTN c.62160A>G (p.Ile20720Met) results in a conservative amino acid change located in the A-band of the encoded protein sequence. Four of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00014 in 242716 control chromosomes, predominantly at a frequency of 0.0011 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 2.82 fold of the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Dilated Cardiomyopathy phenotype (0.00039), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. To our knowledge, no occurrence of c.62160A>G in individuals affected with Dilated Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Eight clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Multiple laboratories reported the variant with conflicting assessments. Based on the evidence outlined above, the variant was classified as likely benign.
Ambry Genetics	RCV002326873	SCV002629946	likely benign	Cardiovascular phenotype	2019-11-05	criteria provided, single submitter	clinical testing	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.
Revvity Omics, Revvity	RCV000723936	SCV003821691	uncertain significance	not provided	2020-09-01	criteria provided, single submitter	clinical testing