15-34792528-G-C

Position:

• chr15-34792528-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_005159.5(ACTC1):​c.496C>G​(p.Pro166Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: ACTC1 NM_005159.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 10.0

Genes affected

ACTC1 (HGNC:143): (actin alpha cardiac muscle 1) Actins are highly conserved proteins that are involved in various types of cell motility. Polymerization of globular actin (G-actin) leads to a structural filament (F-actin) in the form of a two-stranded helix. Each actin can bind to four others. The protein encoded by this gene belongs to the actin family which is comprised of three main groups of actin isoforms, alpha, beta, and gamma. The alpha actins are found in muscle tissues and are a major constituent of the contractile apparatus. Defects in this gene have been associated with idiopathic dilated cardiomyopathy (IDC) and familial hypertrophic cardiomyopathy (FHC). [provided by RefSeq, Jul 2008]

ACTC1 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), ACTC1. . Gene score misZ 4.5244 (greater than the threshold 3.09). Trascript score misZ 6.3156 (greater than threshold 3.09). GenCC has associacion of gene with dilated cardiomyopathy, hypertrophic cardiomyopathy, atrial septal defect 5, arrhythmogenic right ventricular cardiomyopathy, familial isolated dilated cardiomyopathy, dilated cardiomyopathy 1R, hypertrophic cardiomyopathy 11.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ACTC1	NM_005159.5	c.496C>G	p.Pro166Ala	missense_variant	4/7	ENST00000290378.6	NP_005150.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACTC1	ENST00000290378.6	c.496C>G	p.Pro166Ala	missense_variant	4/7	1	NM_005159.5	ENSP00000290378.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy 11 Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Sep 01, 2000

- -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 14, 2023

The p.P166A variant (also known as c.496C>G), located in coding exon 3 of the ACTC1 gene, results from a C to G substitution at nucleotide position 496. The proline at codon 166 is replaced by alanine, an amino acid with highly similar properties. This variant (also referred to as Pro164Ala) occurred de novo in a case with pediatric onset hypertrophic cardiomyopathy (Olson TM et al. J Mol Cell Cardiol, 2000 Sep;32:1687-94). This variant has also been detected in a biobank cohort not selected for the presence of cardiovascular disease; however, clinical details were limited (Wright CF et al. Am J Hum Genet. 2019 Feb;104(2):275-286). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.97	D
M_CAP	Pathogenic	0.63	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	H
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-6.3	D
REVEL	Pathogenic	0.96
Sift4G	Uncertain	0.0090	D
Polyphen		0.56	P
Vest4		0.95
MutPred		0.95		Loss of glycosylation at T162 (P = 0.1601);
MVP		1.0
MPC		2.8
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.90
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
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

Publications

LitVar

Other links and lift over

dbSNP: rs267606628; hg19: chr15-35084729;