chr3-52453991-C-T

Position:

• chr3-52453991-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_003280.3(TNNC1):​c.24+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.0000167 in 1,435,014 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000017 (0 hom.)
• Consequence: TNNC1 NM_003280.3 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.38

Genes affected

TNNC1 (HGNC:11943): (troponin C1, slow skeletal and cardiac type) Troponin is a central regulatory protein of striated muscle contraction, and together with tropomyosin, is located on the actin filament. Troponin consists of 3 subunits: TnI, which is the inhibitor of actomyosin ATPase; TnT, which contains the binding site for tropomyosin; and TnC, the protein encoded by this gene. The binding of calcium to TnC abolishes the inhibitory action of TnI, thus allowing the interaction of actin with myosin, the hydrolysis of ATP, and the generation of tension. Mutations in this gene are associated with cardiomyopathy dilated type 1Z. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• BS2: High AC in GnomAdExome4 at 24 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TNNC1	NM_003280.3	c.24+1G>A		splice_donor_variant, intron_variant		ENST00000232975.8	NP_003271.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TNNC1	ENST00000232975.8	c.24+1G>A		splice_donor_variant, intron_variant		1	NM_003280.3	ENSP00000232975.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000481 AC: 1 AN: 207776 Hom.: 0 AF XY: 0.00000895 AC XY: 1 AN XY: 111712

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: 0.0000112

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000167 AC: 24 AN: 1435014 Hom.: 0 Cov.: 33 AF XY: 0.00000984 AC XY: 7 AN XY: 711210

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: 0.0000121

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000210

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000833 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Aug 11, 2013

Variant classified as Uncertain Significance - Favor Pathogenic. The 24+1G>A var iant in TNNC1 has not been reported in individuals with cardiomyopathy. Data fro m large population studies is insufficient to assess the frequency of this varia nt. This variant occurs in the invariant region (+/- 1,2) of the splice consensu s sequence and is predicted to cause altered splicing leading to an abnormal or absent protein. Although this variant is predicted to be deleterious to the prot ein, the variant spectrum of this gene has not been well characterized and it is unclear if loss-of-function variants play a role in disease. Additional informa tion is needed to fully assess the clinical significance of this variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	35
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Uncertain	0.97	D
GERP RS		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.61		Position offset: -16
DS_DL_spliceai		0.98		Position offset: 1

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

Publications

LitVar

Other links and lift over

dbSNP: rs727503498; hg19: chr3-52488007;