Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2
The NM_001276345.2(TNNT2):c.720-6G>A variant causes a splice region, splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000372 in 1,613,614 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
TNNT2 (HGNC:11949): (troponin T2, cardiac type) This gene encodes the cardiac isoform of troponin T. The encoded protein is the tropomyosin-binding subunit of the troponin complex, which is located on the thin filament of striated muscles and regulates muscle contraction in response to alterations in intracellular calcium ion concentration. Mutations in this gene have been associated with familial hypertrophic cardiomyopathy as well as with dilated cardiomyopathy. [provided by RefSeq, May 2022]
Computational evidence support a benign effect (BayesDel_noAF=-0.91).
BP6
Variant 1-201361375-C-T is Benign according to our data. Variant chr1-201361375-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 43665.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=5, Benign=1}. Variant chr1-201361375-C-T is described in Lovd as [Likely_benign].
Uncertain significance, criteria provided, single submitter
clinical testing
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Nov 19, 2019
Variant summary: TNNT2 c.690-6G>A 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. 5/5 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.6e-05 in 251442 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.690-6G>A has been reported in the literature in individuals affected with dilated- and hypertrophic cardiomyopathy (Morales_2010, Pugh_2014). These reports however, do not provide unequivocal conclusions about association of the variant with the disease. 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 both of them classified the variant as benign (1x) or likely benign (1x). Based on the evidence outlined above, the variant was classified as VUS-possibly benign. -
Benign, criteria provided, single submitter
clinical testing
GeneDx
May 08, 2015
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. -
Cardiomyopathy Benign:2
Likely benign, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Oct 22, 2019
- -
Likely benign, criteria provided, single submitter
clinical testing
All of Us Research Program, National Institutes of Health
Jan 03, 2024
- -
Dilated cardiomyopathy 1D Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
Apr 28, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). Publications were found based on this search. However, the evidence from the literature, in combination with allele frequency data from public databases where available, was not sufficient to rule this variant in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
not provided Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Feb 07, 2023
The c.690-6G>A variant in TNNT2 has been identified in 2 individuals with dilated cardiomyopathy (DCM) who also carried a potentially disease-causing variant in TNNT2, which was confirmed in cis in one of these individuals, as well as 1 individual with hypertrophic cardiomyopathy (HCM; Morales 2010 PMID: 20973921, Ntusi 2016 PMID: 27841901, LMM data). This variant has also been reported by other clinical laboratories in ClinVar (Variation ID 43665) and has been identified in 0.00065% (1/15284) of Latino chromosomes by gnomAD (http://gnomad.broadinstitute.org, v.3.2.1). This variant is located in the 3' splice region. Computational tools do not suggest an impact to splicing. However, this information is not predictive enough to rule out pathogenicity. In summary, while the clinical significance of this variant is uncertain, these data suggest that it is more likely to be benign. ACMG/AMP Criteria applied: BP2, PM2_Supporting. -
Uncertain significance, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
Apr 28, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Hypertrophic cardiomyopathy 2 Uncertain:1
Uncertain significance, criteria provided, single submitter
clinical testing
Illumina Laboratory Services, Illumina
Apr 28, 2017
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -