NM_003280.3:c.23C>A

Variant names:

• chr3-52453993-G-T
• rs267607125
• NM_003280.3:c.23C>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The NM_003280.3(TNNC1):​c.23C>A​(p.Ala8Glu) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000698 in 1,433,628 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A8V) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: TNNC1 NM_003280.3 missense, splice_region
• Scores: Splicing: ADA: 0.9886
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.11
• Publications: 0 publications found

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]

TNNC1 Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1Z

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: PanelApp Australia, Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 13

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_003280.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-52453993-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 12443.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 11 curated pathogenic missense variants (we use a threshold of 10). The gene has 0 curated benign missense variants. Gene score misZ: 1.7682 (below the threshold of 3.09). Trascript score misZ: 2.6866 (below the threshold of 3.09). GenCC associations: The gene is linked to hypertrophic cardiomyopathy 13, dilated cardiomyopathy 1Z, familial isolated dilated cardiomyopathy, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003280.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TNNC1	NM_003280.3	MANE Select	c.23C>A	p.Ala8Glu	missense splice_region	Exon 1 of 6	NP_003271.1	P63316

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TNNC1	ENST00000232975.8	TSL:1 MANE Select	c.23C>A	p.Ala8Glu	missense splice_region	Exon 1 of 6	ENSP00000232975.3	P63316

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.98e-7 AC: 1 AN: 1433628 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 710592

African (AFR) AF: 0.00 AC: 0 AN: 32912

American (AMR) AF: 0.00 AC: 0 AN: 41810

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25492

East Asian (EAS) AF: 0.00 AC: 0 AN: 38390

South Asian (SAS) AF: 0.00 AC: 0 AN: 82496

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50990

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5732

European-Non Finnish (NFE) AF: 9.12e-7 AC: 1 AN: 1096584

Other (OTH) AF: 0.00 AC: 0 AN: 59222

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.81
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	32
DANN	Uncertain	0.99
DEOGEN2	Benign	0.33	T
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.84	T
M_CAP	Uncertain	0.17	D
MetaRNN	Pathogenic	0.83	D
MetaSVM	Uncertain	0.60	D
MutationAssessor	Benign	0.94	L
PhyloP100		8.1
PrimateAI	Pathogenic	0.91	D
PROVEAN	Benign	-0.61	N
REVEL	Pathogenic	0.76
Sift	Uncertain	0.028	D
Sift4G	Benign	0.22	T
Polyphen		0.82	P
Vest4		0.87
MutPred		0.61		Gain of disorder (P = 0.0168)
MVP		0.96
MPC		2.5
ClinPred		0.91	D
GERP RS		4.7
PromoterAI		0.042	Neutral
Varity_R		0.76
gMVP		0.99
Mutation Taster		=4/96	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs267607125; hg19: chr3-52488009;