rs397516449

chr1-201366832-A-G

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_Moderate BP6

The NM_001276345.2(TNNT2):c.233+6T>C variant causes a splice donor region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000391 in 1,613,134 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000042 (0 hom.)
• Consequence: TNNT2 NM_001276345.2 splice_donor_region, intron
• Scores: Splicing: ADA: 0.002346
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6 B:2
• Conservation: PhyloP100: 1.94

Genes affected

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]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.41).
• BP6: Variant 1-201366832-A-G is Benign according to our data. Variant chr1-201366832-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 43616.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=6, Likely_benign=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TNNT2	NM_001276345.2	c.233+6T>C		splice_donor_region_variant, intron_variant		ENST00000656932.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TNNT2	ENST00000656932.1	c.233+6T>C		splice_donor_region_variant, intron_variant			NM_001276345.2	A2

Frequencies

GnomAD3 genomes AF: 0.0000132 AC: 2 AN: 151270 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000295

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251462 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135906

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000417 AC: 61 AN: 1461864 Hom.: 0 Cov.: 34 AF XY: 0.0000468 AC XY: 34 AN XY: 727236

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000132 AC: 2 AN: 151270 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 73820

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000295

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000151

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cardiomyopathy Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Nov 16, 2018	- -
Likely benign, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Dec 01, 2023	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Dec 26, 2013

The 203+6T>C variant in TNNT2 has been previously identified by our laboratory i n 1 individual with early-onset DCM and this individual's unaffected parent, but has not been reported in the literature in any other families with DCM or in la rge population studies. This variant is located in the 5' splice region. Computa tional tools do not strongly suggest an impact to splicing. However, this inform ation is not predictive enough to rule out pathogenicity. In summary, additional studies are needed to fully assess the clinical significance of this variant. -

Dilated cardiomyopathy 1D Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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. -

Left ventricular noncompaction cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jun 14, 2016

- -

Cardiomyopathy, familial restrictive, 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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. -

Hypertrophic cardiomyopathy 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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. -

Dilated cardiomyopathy 1D;C1861864:Hypertrophic cardiomyopathy 2;C2676271:Cardiomyopathy, familial restrictive, 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 15, 2023

ClinVar contains an entry for this variant (Variation ID: 43616). 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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. This variant has not been reported in the literature in individuals affected with TNNT2-related conditions. This variant is present in population databases (rs397516449, gnomAD 0.0009%). This sequence change falls in intron 7 of the TNNT2 gene. It does not directly change the encoded amino acid sequence of the TNNT2 protein. It affects a nucleotide within the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.41
Cadd	Benign	16
Dann	Benign	0.88

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0023
dbscSNV1_RF	Benign	0.094
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs397516449; hg19: chr1-201335960;