NM_001100.4:c.132C>T

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_001100.4(ACTA1):​c.132C>T​(p.Gly44Gly) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00011 in 1,614,148 control chromosomes in the GnomAD database, including 3 homozygotes. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00069 ( 2 hom., cov: 32)
Exomes 𝑓: 0.000049 ( 1 hom. )

Consequence

ACTA1
NM_001100.4 splice_region, synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:4

Conservation

PhyloP100: 1.15

Publications

0 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: Benign. The variant received -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.51).
BP6
Variant 1-229432878-G-A is Benign according to our data. Variant chr1-229432878-G-A is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 128259.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=1.15 with no splicing effect.
BS1
Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.00069 (105/152274) while in subpopulation AMR AF = 0.00588 (90/15306). AF 95% confidence interval is 0.0049. There are 2 homozygotes in GnomAd4. There are 46 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 2 SD,AD,AR,Unknown gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001100.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ACTA1
NM_001100.4
MANE Select
c.132C>Tp.Gly44Gly
splice_region synonymous
Exon 3 of 7NP_001091.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
ACTA1
ENST00000366684.7
TSL:1 MANE Select
c.132C>Tp.Gly44Gly
splice_region synonymous
Exon 3 of 7ENSP00000355645.3
ACTA1
ENST00000684723.1
c.-4C>T
splice_region
Exon 2 of 6ENSP00000508084.1
ACTA1
ENST00000366683.4
TSL:5
c.132C>Tp.Gly44Gly
splice_region synonymous
Exon 3 of 7ENSP00000355644.4

Frequencies

GnomAD3 genomes
AF:
0.000684
AC:
104
AN:
152156
Hom.:
2
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000145
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00582
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:
0.00430
GnomAD2 exomes
AF:
0.0000917
AC:
23
AN:
250754
AF XY:
0.000111
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000549
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:
0.000654
GnomAD4 exome
AF:
0.0000493
AC:
72
AN:
1461874
Hom.:
1
Cov.:
38
AF XY:
0.0000523
AC XY:
38
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000984
AC:
44
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:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112004
Other (OTH)
AF:
0.000447
AC:
27
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.497
Heterozygous variant carriers
0
6
12
18
24
30
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
AF:
0.000690
AC:
105
AN:
152274
Hom.:
2
Cov.:
32
AF XY:
0.000618
AC XY:
46
AN XY:
74466
show subpopulations
African (AFR)
AF:
0.000144
AC:
6
AN:
41554
American (AMR)
AF:
0.00588
AC:
90
AN:
15306
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5164
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68006
Other (OTH)
AF:
0.00425
AC:
9
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.496
Heterozygous variant carriers
0
5
10
15
20
25
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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
Alfa
AF:
0.0000959
Hom.:
0
Bravo
AF:
0.00138

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:2
Jun 03, 2016
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease.

Aug 26, 2013
Genetic Services Laboratory, University of Chicago
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Actin accumulation myopathy Benign:1
Jan 15, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Congenital myopathy with fiber type disproportion Benign:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.51
CADD
Benign
13
DANN
Benign
0.78
PhyloP100
1.1
Mutation Taster
=79/21
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs146956806; hg19: chr1-229568625; API