Submissions for variant NM_001267550.2(TTN):c.1398+8C>T

gnomAD frequency: 0.01171  dbSNP: rs72647848

Total submissions: 18

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	RCV000039899	SCV000063590	benign	not specified	2012-07-31	criteria provided, single submitter	clinical testing
Genetic Services Laboratory, University of Chicago	RCV000039899	SCV000153179	benign	not specified	2015-02-10	criteria provided, single submitter	clinical testing
GeneDx	RCV000039899	SCV000169242	benign	not specified	2014-04-07	criteria provided, single submitter	clinical testing	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.
Invitae	RCV000231254	SCV000286445	benign	Dilated cardiomyopathy 1G; Autosomal recessive limb-girdle muscular dystrophy type 2J	2024-02-01	criteria provided, single submitter	clinical testing
Illumina Laboratory Services, Illumina	RCV000268952	SCV000425270	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	RCV000326401	SCV000425271	benign	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 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	RCV000286415	SCV000425273	likely benign	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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease.
Illumina Laboratory Services, Illumina	RCV000339221	SCV000425274	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	RCV000377441	SCV000425275	likely benign	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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease.
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV000039899	SCV001361741	benign	not specified	2019-11-06	criteria provided, single submitter	clinical testing	Variant summary: TTN c.1398+8C>T alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 5 computational tools predict that the variant does not affect the canonical splice site, while 2 predict that the variant creates an additional, weak intronic 5' donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.0028 in 251132 control chromosomes, predominantly at a frequency of 0.038 within the African or African-American subpopulation in the gnomAD database (exome dataset), including 20 homozygotes. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 60-fold the estimated maximal expected allele frequency for a pathogenic variant in TTN causing Cardiomyopathy phenotype (0.00063), 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.1398+8C>T in individuals affected with Cardiomyopathy and no experimental evidence demonstrating its impact on protein function have been reported. Co-occurrence with another pathogenic variant has been reported (TTR c.424G>A, p.Val142Ile; internal sample), providing supporting evidence for a benign role. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as benign.
Genome-Nilou Lab	RCV000286415	SCV002101633	benign	Autosomal recessive limb-girdle muscular dystrophy type 2J	2021-09-10	criteria provided, single submitter	clinical testing
Genome-Nilou Lab	RCV000268952	SCV002101635	benign	Myopathy, myofibrillar, 9, with early respiratory failure	2021-09-10	criteria provided, single submitter	clinical testing
Genome-Nilou Lab	RCV000326401	SCV002101636	benign	Early-onset myopathy with fatal cardiomyopathy	2021-09-10	criteria provided, single submitter	clinical testing
Genome-Nilou Lab	RCV000339221	SCV002101637	benign	Tibial muscular dystrophy	2021-09-10	criteria provided, single submitter	clinical testing
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	RCV001795014	SCV004562780	benign	not provided	2022-12-21	criteria provided, single submitter	clinical testing
Clinical Genetics, Academic Medical Center	RCV000039899	SCV001917966	benign	not specified		no assertion criteria provided	clinical testing
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	RCV000039899	SCV001964143	benign	not specified		no assertion criteria provided	clinical testing
Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	RCV001795014	SCV002036238	likely benign	not provided		no assertion criteria provided	clinical testing