rs546670743

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_001100.4(ACTA1):​c.82G>T​(p.Ala28Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,862 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A28C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

ACTA1
NM_001100.4 missense

Scores

6
8
5

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.89

Publications

1 publications found
Variant links:
Genes affected
ACTA1 (HGNC:129): (actin alpha 1, skeletal muscle) The product encoded by this gene belongs to the actin family of proteins, which are highly conserved proteins that play a role in cell motility, structure and integrity. Alpha, beta and gamma actin isoforms have been identified, with alpha actins being a major constituent of the contractile apparatus, while beta and gamma actins are involved in the regulation of cell motility. This actin is an alpha actin that is found in skeletal muscle. Mutations in this gene cause a variety of myopathies, including nemaline myopathy, congenital myopathy with excess of thin myofilaments, congenital myopathy with cores, and congenital myopathy with fiber-type disproportion, diseases that lead to muscle fiber defects with manifestations such as hypotonia. [provided by RefSeq, Sep 2019]
ACTA1 Gene-Disease associations (from GenCC):
  • alpha-actinopathy
    Inheritance: AR, AD Classification: DEFINITIVE Submitted by: ClinGen
  • congenital myopathy 2a, typical, autosomal dominant
    Inheritance: AR, SD, AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • congenital myopathy with excess of thin filaments
    Inheritance: SD Classification: DEFINITIVE Submitted by: Illumina
  • congenital myopathy 2c, severe infantile, autosomal dominant
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • childhood-onset nemaline myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • congenital fiber-type disproportion myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • intermediate nemaline myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • progressive scapulohumeroperoneal distal myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • typical nemaline myopathy
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • rigid spine syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • severe congenital nemaline myopathy
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • zebra body myopathy
    Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_001100.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the ACTA1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 154 curated pathogenic missense variants (we use a threshold of 10). The gene has 0 curated benign missense variants. Gene score misZ: 4.5292 (above the threshold of 3.09). Trascript score misZ: 6.088 (above the threshold of 3.09). GenCC associations: The gene is linked to congenital myopathy with excess of thin filaments, congenital fiber-type disproportion myopathy, severe congenital nemaline myopathy, congenital myopathy 2a, typical, autosomal dominant, zebra body myopathy, alpha-actinopathy, rigid spine syndrome, progressive scapulohumeroperoneal distal myopathy, childhood-onset nemaline myopathy, typical nemaline myopathy, intermediate nemaline myopathy, congenital myopathy 2c, severe infantile, autosomal dominant.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ACTA1NM_001100.4 linkc.82G>T p.Ala28Ser missense_variant Exon 2 of 7 ENST00000366684.7 NP_001091.1 P68133

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ACTA1ENST00000366684.7 linkc.82G>T p.Ala28Ser missense_variant Exon 2 of 7 1 NM_001100.4 ENSP00000355645.3 P68133
ACTA1ENST00000366683.4 linkc.82G>T p.Ala28Ser missense_variant Exon 2 of 7 5 ENSP00000355644.4 A6NL76
ACTA1ENST00000684723.1 linkc.-6-154G>T intron_variant Intron 1 of 5 ENSP00000508084.1 A0A804HKV3

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152200
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000799
AC:
2
AN:
250200
AF XY:
0.00000738
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
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:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461544
Hom.:
0
Cov.:
38
AF XY:
0.00000275
AC XY:
2
AN XY:
727082
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.0000447
AC:
2
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53268
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111854
Other (OTH)
AF:
0.00
AC:
0
AN:
60376
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152318
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74472
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41588
American (AMR)
AF:
0.0000653
AC:
1
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5168
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10626
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68014
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Actin accumulation myopathy Uncertain:1
Jul 05, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals affected with ACTA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1428668). 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 expected to disrupt ACTA1 protein function. 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. This variant is present in population databases (rs546670743, gnomAD 0.006%). This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 28 of the ACTA1 protein (p.Ala28Ser). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.71
BayesDel_addAF
Uncertain
0.070
D
BayesDel_noAF
Uncertain
0.040
CADD
Pathogenic
27
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.82
D;T
Eigen
Benign
0.13
Eigen_PC
Benign
0.22
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.94
D;D
M_CAP
Uncertain
0.23
D
MetaRNN
Uncertain
0.74
D;D
MetaSVM
Uncertain
0.37
D
MutationAssessor
Uncertain
2.4
M;.
PhyloP100
7.9
PrimateAI
Pathogenic
0.86
D
PROVEAN
Benign
-1.5
N;N
REVEL
Pathogenic
0.69
Sift
Pathogenic
0.0
.;D
Sift4G
Benign
0.11
T;T
Polyphen
0.0
B;.
Vest4
0.68
MutPred
0.83
Gain of disorder (P = 0.0401);Gain of disorder (P = 0.0401);
MVP
0.97
ClinPred
0.88
D
GERP RS
4.7
Varity_R
0.88
gMVP
0.88
Mutation Taster
=5/95
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs546670743; hg19: chr1-229568781; API