Submissions for variant NM_001267550.2(TTN):c.96235G>A (p.Asp32079Asn)

dbSNP: rs200540781

Total submissions: 16

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
GeneDx	RCV000725268	SCV000237820	likely benign	not provided	2021-06-08	criteria provided, single submitter	clinical testing
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	RCV000219446	SCV000272810	uncertain significance	not specified	2015-03-24	criteria provided, single submitter	clinical testing	The p.Asp29511Asn variant in TTN has not been previously reported in individuals with cardiomyopathy, but has been identified in 12/66690 European chromosomes a nd 6/11544 Latino chromosomes by the Exome Aggregation Consortium (ExAC, http:// exac.broadinstitute.org; dbSNP rs200540781). Computational prediction tools and conservation analysis suggest that this variant may impact the protein, though t his information is not predictive enough to determine pathogenicity. In summary, the clinical significance of the p.Asp29511Asn variant is uncertain.
Eurofins Ntd Llc (ga)	RCV000725268	SCV000335505	uncertain significance	not provided	2015-09-22	criteria provided, single submitter	clinical testing
Illumina Laboratory Services, Illumina	RCV000273519	SCV000420607	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.
Illumina Laboratory Services, Illumina	RCV000334102	SCV000420608	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	RCV000388603	SCV000420609	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	RCV000316543	SCV000420611	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	RCV000375971	SCV000420612	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.
Labcorp Genetics (formerly Invitae), Labcorp	RCV000464293	SCV000542406	uncertain significance	Dilated cardiomyopathy 1G; Autosomal recessive limb-girdle muscular dystrophy type 2J	2017-04-06	criteria provided, single submitter	clinical testing
Ambry Genetics	RCV000617391	SCV000736061	likely benign	Cardiovascular phenotype	2019-09-25	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	RCV000725268	SCV003827906	uncertain significance	not provided	2023-12-08	criteria provided, single submitter	clinical testing
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario	RCV003150052	SCV003838517	likely benign	Cardiomyopathy	2023-05-26	criteria provided, single submitter	clinical testing
Clinical Center for Gene Diagnosis and Therapy, Department of Cardiovascular Surgery, The Second Xiangya Hospital of Central South University	RCV003319185	SCV003932375	uncertain significance	Primary dilated cardiomyopathy	2023-06-01	criteria provided, single submitter	clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp	RCV000219446	SCV004029881	likely benign	not specified	2023-07-05	criteria provided, single submitter	clinical testing	Variant summary: TTN c.88531G>A (p.Asp29511Asn) results in a conservative amino acid change located in the A-band domain of the encoded protein sequence. Three of four in-silico tools predict a damaging effect of the variant on protein function. The observed variant frequency within Latino control individuals in the gnomAD database is approximately 1.1 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 Latino origin. c.88531G>A has been reported in the literature in individuals affected with sudden unexplained death/sudden infant death syndrome or fetal loss without evidence for causality (examples: Campuzano_2015, Kline_2021). These report(s) do not provide unequivocal conclusions about association of the variant with Dilated Cardiomyopathy. Co-occurrence with a pathogenic variant have been reported (TTN c.38632A>T, p.Arg12878X), providing supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 26516846, 34756330). Eight submitters have cited clinical-significance assessments for this variant to ClinVar after 2014, classifying the variant as likely benign (n=2) or uncertain significance (n=6). Based on the evidence outlined above, the variant was classified as likely benign.
Department of Pathology and Laboratory Medicine, Sinai Health System	RCV000725268	SCV001552760	uncertain significance	not provided		no assertion criteria provided	clinical testing	The TTN p.Asp23014Asn variant was not identified in the literature but was identified in dbSNP (ID: rs200540781), ClinVar (classified as uncertain significance by GeneDx, Invitae, Ambry Genetics, EGL Genetic Diagnostics, Laboratory for Molecular Medicine and Invitae) and LOVD 3.0 (classified as a VUS). The variant was identified in control databases in 51 of 280188 chromosomes at a frequency of 0.000182 (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the following populations: Latino in 15 of 35360 chromosomes (freq: 0.000424), Other in 2 of 7126 chromosomes (freq: 0.000281), European (non-Finnish) in 32 of 128056 chromosomes (freq: 0.00025) and African in 2 of 24182 chromosomes (freq: 0.000083), but was not observed in the Ashkenazi Jewish, East Asian, European (Finnish), or South Asian populations. The p.Asp23014 residue has limited species conservation information and computational analyses (PolyPhen-2, BLOSUM, MutationTaster) provide inconsistent predictions regarding the impact to the protein. The variant occurs outside of the splicing consensus sequence and three of four in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) predict a greater than 10% difference in splicing. However, this information is not predictive enough to assume pathogenicity. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance.
PreventionGenetics, part of Exact Sciences	RCV004734792	SCV005358499	uncertain significance	TTN-related disorder	2024-04-04	no assertion criteria provided	clinical testing	The TTN c.96235G>A variant is predicted to result in the amino acid substitution p.Asp32079Asn. This variant was reported in individuals with sudden unexplained death; however, detailed clinical information was not available (described as p.29511D>N in Table S1, Campuzano et al. 2015. PubMed ID: 26516846; Rohrer et al. 2023. PubMed ID: 37614113). This variant is reported in 0.042% of alleles in individuals of Latino descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence.