Submissions for variant NM_001267550.2(TTN):c.98759G>A (p.Arg32920Gln)

gnomAD frequency: 0.00004  dbSNP: rs752015224

Total submissions: 6

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Biesecker Lab/Clinical Genomics Section, National Institutes of Health	RCV000172177	SCV000051101	uncertain significance	not provided	2013-06-24	criteria provided, single submitter	research
GeneDx	RCV000412704	SCV000237858	uncertain significance	not specified	2014-08-18	criteria provided, single submitter	clinical testing	Missense variants in the TTN gene are considered 'unclassified' if they are not previously reported in the literature and do not have >1% frequency in the population to be considered a polymorphism. Research indicates that truncating mutations in the TTN gene are expected to account for approximately 25% of familial and 18% of sporadic idiopathic DCM; however, truncating variants in the TTN gene have been reported in approximately 3% of reported control alleles. There has been little investigation into non-truncating variants. (Herman D et al. Truncations of titin causing dilated cardiomyopathy. N Eng J Med 366:619-628, 2012) The variant is found in DCM-CRDM panel(s).
Ambry Genetics	RCV000617797	SCV000736891	uncertain significance	Cardiovascular phenotype	2017-08-08	criteria provided, single submitter	clinical testing	The p.R23855Q variant (also known as c.71564G>A), located in coding exon 180 of the TTN gene, results from a G to A substitution at nucleotide position 71564. The arginine at codon 23855 is replaced by glutamine, an amino acid with highly similar properties. This alteration has been reported as a secondary cardiac variant in an exome cohort (Ng D et al. Circ Cardiovasc Genet, 2013 Aug;6:337-46). This amino acid position is highly conserved in available 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.
Invitae	RCV000687392	SCV000814956	uncertain significance	Dilated cardiomyopathy 1G; Autosomal recessive limb-girdle muscular dystrophy type 2J	2018-01-29	criteria provided, single submitter	clinical testing	This sequence change replaces arginine with glutamine at codon 32920 of the TTN protein (p.Arg32920Gln). There is a small physicochemical difference between arginine and glutamine. This variant is present in population databases (rs752015224, ExAC 0.02%). This variant has not been reported in the literature in individuals with TTN-related disease. ClinVar contains an entry for this variant (Variation ID: 191836). This variant identified in the TTN gene is located in the A band of the resulting protein (PMID: 25589632). It is unclear how this variant impacts the function of this protein. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. Algorithms developed to predict the effect of missense changes on protein structure and function are unavailable for the TTN gene. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance.
Fulgent Genetics, Fulgent Genetics	RCV002492723	SCV002782502	uncertain significance	Dilated cardiomyopathy 1G; Autosomal recessive limb-girdle muscular dystrophy type 2J; Tibial muscular dystrophy; Myopathy, myofibrillar, 9, with early respiratory failure; Early-onset myopathy with fatal cardiomyopathy; Hypertrophic cardiomyopathy 9	2021-08-17	criteria provided, single submitter	clinical testing
Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen	RCV000491239	SCV000298139	uncertain significance	Dilated cardiomyopathy 1S	2016-05-01	no assertion criteria provided	research