15-34794740-A-C

Position:

• chr15-34794740-A-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.69T>G​(p.Phe23Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ACTC1 NM_005159.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.02

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]

GJD2-DT (HGNC:55560): (GJD2 divergent transcript)

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, 0.966

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACTC1	NM_005159.5	c.69T>G	p.Phe23Leu	missense_variant	2/7	ENST00000290378.6
GJD2-DT	NR_120329.1	n.300-15756A>C		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACTC1	ENST00000290378.6	c.69T>G	p.Phe23Leu	missense_variant	2/7	1	NM_005159.5	P1
GJD2-DT	ENST00000671663.1	n.95-15756A>C		intron_variant, non_coding_transcript_variant
ACTC1	ENST00000560563.2	n.175T>G		non_coding_transcript_exon_variant	2/6	2
GJD2-DT	ENST00000503496.6	n.300-15756A>C		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 21, 2022

The p.F23L variant (also known as c.69T>G), located in coding exon 1 of the ACTC1 gene, results from a T to G substitution at nucleotide position 69. The phenylalanine at codon 23 is replaced by leucine, an amino acid with highly similar properties. A different alteration located at the same position, resulting in the same protein change, c.67T>C p.F23L, was observed in two individuals reported to have hypertrophic cardiomyopathy; however, clinical details were limited (Coppini R et al. J Am Coll Cardiol. 2014;64:2589-600). 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	1.0
CardioboostCm	Pathogenic	0.90
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Benign	-0.15
Eigen_PC	Benign	-0.16
FATHMM_MKL	Uncertain	0.83	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.54	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Uncertain	0.61	D
MutationAssessor	Benign	2.0	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Benign	-2.2	N
REVEL	Pathogenic	0.81
Sift4G	Benign	0.067	T
Polyphen		0.23	B
Vest4		0.84
MutPred		0.86		Loss of catalytic residue at F23 (P = 0.0352);
MVP		1.0
MPC		3.2
ClinPred		0.90	D
GERP RS		-0.64
Varity_R		0.66
gMVP		0.98

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: rs1555419008; hg19: chr15-35086941;