Submissions for variant NM_001267550.2(TTN):c.21142C>T (p.Arg7048Ter)

gnomAD frequency: 0.00001  dbSNP: rs770579313

Total submissions: 3

Submitter	RCV	SCV	Clinical significance	Condition	Last evaluated	Review status	Method	Comment
Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust	RCV000208995	SCV000189717	uncertain significance	Primary dilated cardiomyopathy	2014-10-08	criteria provided, single submitter	research	This TTN truncating variant (TTNtv) was identified in one individual in this cohort and is located in an exon with intermediate levels of cardiac expression. In the seven cohorts assessed, TTNtv were found in 14% of ambulant DCM, 22% end-stage or familial DCM, and 2% controls. Heterozygous nonsense, frameshift and canonical splice-disrupting variants found in constitutive and other highly utilised exons are highly likely to be pathogenic when identified in individuals with phenotypically confirmed DCM. TTNtv found incidentally in healthy individuals (excluding familial assessment of DCM relatives) are thought to have low penetrance, particularly when identified in exons that are not constitutively expressed in the heart.
Eurofins Ntd Llc (ga)	RCV000376176	SCV000339259	uncertain significance	not provided	2016-02-08	criteria provided, single submitter	clinical testing
Invitae	RCV002517420	SCV002963479	likely pathogenic	Dilated cardiomyopathy 1G; Autosomal recessive limb-girdle muscular dystrophy type 2J	2024-01-08	criteria provided, single submitter	clinical testing	This sequence change creates a premature translational stop signal (p.Arg7048*) in the TTN gene. While this is not anticipated to result in nonsense mediated decay, it is expected to create a truncated TTN protein. This variant is present in population databases (rs770579313, gnomAD 0.002%). This premature translational stop signal has been observed in individual(s) with clinical features of limb girdle muscular dystrophy (PMID: 31618753). ClinVar contains an entry for this variant (Variation ID: 223333). This variant is located in the I band of TTN (PMID: 25589632). Truncating variants in this region have been reported in individuals affected with autosomal recessive centronuclear myopathy (PMID: 23975875, Invitae internal data). Truncating variants in this region have also been identified in individuals affected with autosomal dominant dilated cardiomyopathy and/or cardio-related conditions (PMID: 27869827, 32964742, Invitae internal data). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic.