Our verdict is Benign. Variant got -16 ACMG points: 0P and 16B. BP6_Very_StrongBS1BS2
The NM_001276345.2(TNNT2):c.412-6_412-4del 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 0.0000813 in 1,612,288 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).
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]
Variant 1-201364378-AAGG-A is Benign according to our data. Variant chr1-201364378-AAGG-A is described in ClinVar as [Likely_benign]. Clinvar id is 43635.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-201364378-AAGG-A is described in Lovd as [Likely_benign].
BS1
Variant frequency is greater than expected in population eas. gnomad4_exome allele frequency = 0.0000849 (124/1459950) while in subpopulation EAS AF= 0.00297 (118/39700). AF 95% confidence interval is 0.00254. There are 0 homozygotes in gnomad4_exome. There are 70 alleles in male gnomad4_exome subpopulation. This position pass quality control queck.
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Jun 12, 2023
Variant summary: TNNT2 c.382-6_382-4delCCT alters a nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 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 0.00012 in 249246 control chromosomes, predominantly at a frequency of 0.0016 within the East Asian subpopulation in the gnomAD database. The observed variant frequency within East Asian control individuals in the gnomAD database is approximately 9 fold of the estimated maximal expected allele frequency for a pathogenic variant in TNNT2 causing Cardiomyopathy phenotype (0.00018), strongly suggesting that the variant is a benign polymorphism found primarily in populations of East Asian origin. c.382-6_382-4delCCT has been reported in the literature in individuals affected with Cardiomyopathy (Lakdawala_2012 and Pugh_2014) without strong evidence for causality. These reports do not provide unequivocal conclusions about association of the variant with Cardiomyopathy. 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: 24503780, 22464770). 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. -
Likely benign, criteria provided, single submitter
clinical testing
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Nov 09, 2010
The 382-6_382-4delCCT variant has not been reported in the literature but has be en detected by our laboratory in two Asian probands, one with HCM and one with D CM. The HCM case already had another variant thought to be causative for disease . In silico tools do not predict an impact to the splicing consensus sequence. I n summary, this data suggests this variant is likely benign. -
Cardiomyopathy Benign:2
Benign, criteria provided, single submitter
clinical testing
CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario
Oct 21, 2020
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Benign, criteria provided, single submitter
clinical testing
Color Diagnostics, LLC DBA Color Health
Jul 03, 2018
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Dilated cardiomyopathy 1D Benign:1
Benign, criteria provided, single submitter
clinical testing
Genome-Nilou Lab
Apr 11, 2023
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Cardiomyopathy, familial restrictive, 3 Benign:1
Benign, criteria provided, single submitter
clinical testing
Genome-Nilou Lab
Apr 11, 2023
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Hypertrophic cardiomyopathy 2 Benign:1
Benign, criteria provided, single submitter
clinical testing
Genome-Nilou Lab
Apr 11, 2023
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Cardiovascular phenotype Benign:1
Likely benign, criteria provided, single submitter
clinical testing
Ambry Genetics
Jan 22, 2020
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. -