Submissions for variant NM_001267550.2(TTN):c.61276C>T (p.Leu20426Phe)

gnomAD frequency: 0.00004  dbSNP: rs377529060

Total submissions: 11

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Illumina Laboratory Services, Illumina	RCV000306892	SCV000422491	benign	Tibial muscular dystrophy	2018-01-12	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	RCV000398857	SCV000422493	uncertain significance	Early-onset myopathy with fatal cardiomyopathy	2018-01-12	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	RCV000310552	SCV000422494	benign	Myopathy, myofibrillar, 9, with early respiratory failure	2018-01-12	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	RCV000358355	SCV000422495	uncertain significance	Dilated cardiomyopathy 1G	2018-01-12	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	RCV000265408	SCV000422496	uncertain significance	Autosomal recessive limb-girdle muscular dystrophy type 2J	2018-01-12	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.
Labcorp Genetics (formerly Invitae), Labcorp	RCV000557466	SCV000643468	likely benign	Dilated cardiomyopathy 1G; Autosomal recessive limb-girdle muscular dystrophy type 2J	2024-01-17	criteria provided, single submitter	clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV001375616	SCV001572535	likely benign	not specified	2021-04-15	criteria provided, single submitter	clinical testing	Variant summary: TTN c.53572C>T (p.Leu17858Phe) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8.5e-05 in 247964 control chromosomes, predominantly at a frequency of 0.001 within the East Asian subpopulation in the gnomAD database, including 1 homozygotes. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 2.5 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 East Asian origin. c.53572C>T has been reported in the literature in at least one individuals affected with Epilepsy (Mao_2017). This report does not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation and classified the variant as likely benign/benign. Based on the evidence outlined above, the variant was classified as likely benign.
Ambry Genetics	RCV002460068	SCV002618407	uncertain significance	Cardiovascular phenotype	2018-11-05	criteria provided, single submitter	clinical testing	The p.L11361F variant (also known as c.34081C>T), located in coding exon 131 of the TTN gene, results from a C to T substitution at nucleotide position 34081. The leucine at codon 11361 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species; however, phenylalanine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.
Revvity Omics, Revvity	RCV003137950	SCV003820216	uncertain significance	not provided	2023-09-25	criteria provided, single submitter	clinical testing
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario	RCV003486817	SCV004239972	likely benign	Cardiomyopathy	2023-06-26	criteria provided, single submitter	clinical testing
PreventionGenetics, part of Exact Sciences	RCV004544611	SCV004788087	likely benign	TTN-related disorder	2023-04-20	no assertion criteria provided	clinical testing	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).