chr15-34793482-T-C

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BS2

The NM_005159.5(ACTC1):​c.217A>G​(p.Ile73Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,894 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. I73I) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

ACTC1
NM_005159.5 missense

Scores

2
11
5

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 8.02

Publications

1 publications found
Variant links:
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)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BS2
High AC in GnomAdExome4 at 7 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005159.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ACTC1
NM_005159.5
MANE Select
c.217A>Gp.Ile73Val
missense
Exon 3 of 7NP_005150.1
ACTC1
NM_001406482.1
c.217A>Gp.Ile73Val
missense
Exon 2 of 6NP_001393411.1
ACTC1
NM_001406483.1
c.217A>Gp.Ile73Val
missense
Exon 3 of 7NP_001393412.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ACTC1
ENST00000290378.6
TSL:1 MANE Select
c.217A>Gp.Ile73Val
missense
Exon 3 of 7ENSP00000290378.4
ACTC1
ENST00000713613.1
c.328A>Gp.Ile110Val
missense
Exon 4 of 8ENSP00000518909.1
ACTC1
ENST00000713610.1
c.217A>Gp.Ile73Val
missense
Exon 3 of 7ENSP00000518905.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251472
AF XY:
0.0000294
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461894
Hom.:
0
Cov.:
31
AF XY:
0.00000825
AC XY:
6
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000580
AC:
5
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1112012
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Uncertain:1
Mar 30, 2015
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Ile73Val variant in ACTC1 has not been previously reported in individuals with cardiomyopathy, but has been identified in 2/16512 South Asian chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org). Comp utational prediction tools and conservation analysis do not provide strong suppo rt for or against an impact the protein. In summary, the clinical significance o f the p.Ile73Val variant is uncertain.

Cardiomyopathy Uncertain:1
Jun 30, 2019
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces isoleucine with valine at codon 73 of the ACTC1 protein. Computational prediction tools and conservation analyses are inconclusive regarding the impact of this variant on the protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 4/251472 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.

Hypertrophic cardiomyopathy 11;C2748552:Atrial septal defect 5;C3150681:Dilated cardiomyopathy 1R Uncertain:1
Mar 19, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 73 of the ACTC1 protein (p.Ile73Val). This variant is present in population databases (rs750951965, gnomAD 0.01%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 32815737). ClinVar contains an entry for this variant (Variation ID: 228429). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt ACTC1 protein function with a negative predictive value of 80%. 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.

Hypertrophic cardiomyopathy Uncertain:1
Dec 01, 2023
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces isoleucine with valine at codon 73 of the ACTC1 protein. Computational prediction tools and conservation analyses are inconclusive regarding the impact of this variant on the protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 4/251472 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance.

Cardiovascular phenotype Uncertain:1
Jun 10, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.I73V variant (also known as c.217A>G), located in coding exon 2 of the ACTC1 gene, results from an A to G substitution at nucleotide position 217. The isoleucine at codon 73 is replaced by valine, an amino acid with highly similar properties. This variant was reported in individual(s) with features consistent with hypertrophic cardiomyopathy (HCM) (Pua CJ et al. Circ Genom Precis Med, 2020 Oct;13:424-434). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
CardioboostCm
Uncertain
0.18
BayesDel_addAF
Uncertain
0.14
D
BayesDel_noAF
Pathogenic
0.16
CADD
Pathogenic
27
DANN
Benign
0.97
DEOGEN2
Uncertain
0.73
D
Eigen
Uncertain
0.26
Eigen_PC
Uncertain
0.40
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.88
D
M_CAP
Uncertain
0.25
D
MetaRNN
Uncertain
0.64
D
MetaSVM
Uncertain
0.60
D
MutationAssessor
Benign
1.6
L
PhyloP100
8.0
PrimateAI
Uncertain
0.62
T
PROVEAN
Benign
-0.55
N
REVEL
Pathogenic
0.69
Sift4G
Benign
0.12
T
Polyphen
0.0040
B
Vest4
0.46
MutPred
0.65
Loss of sheet (P = 0.1158)
MVP
0.97
MPC
1.4
ClinPred
0.46
T
GERP RS
5.5
Varity_R
0.43
gMVP
0.90
Mutation Taster
=36/64
disease causing

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

Other links and lift over

dbSNP: rs750951965; hg19: chr15-35085683; API