chr1-229431988-G-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_001100.4(ACTA1):​c.808+6C>A variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000436 in 1,606,228 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

ACTA1
NM_001100.4 splice_region, intron

Scores

2
Splicing: ADA: 0.0004073
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.927

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: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.45).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ACTA1NM_001100.4 linkc.808+6C>A splice_region_variant, intron_variant Intron 5 of 6 ENST00000366684.7 NP_001091.1 P68133

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ACTA1ENST00000366684.7 linkc.808+6C>A splice_region_variant, intron_variant Intron 5 of 6 1 NM_001100.4 ENSP00000355645.3 P68133
ACTA1ENST00000366683.4 linkc.808+6C>A splice_region_variant, intron_variant Intron 5 of 6 5 ENSP00000355644.4 A6NL76
ACTA1ENST00000684723.1 linkc.673+6C>A splice_region_variant, intron_variant Intron 4 of 5 ENSP00000508084.1 A0A804HKV3
ENSG00000290037ENST00000702606.2 linkn.*127G>T downstream_gene_variant

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152158
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000965
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.00000848
AC:
2
AN:
235838
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.000139
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:
0.00
GnomAD4 exome
AF:
0.00000206
AC:
3
AN:
1453952
Hom.:
0
Cov.:
34
AF XY:
0.00000138
AC XY:
1
AN XY:
722718
show subpopulations
African (AFR)
AF:
0.0000900
AC:
3
AN:
33316
American (AMR)
AF:
0.00
AC:
0
AN:
44094
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25890
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39530
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85658
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52360
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4356
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1108782
Other (OTH)
AF:
0.00
AC:
0
AN:
59966
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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
AF:
0.0000263
AC:
4
AN:
152276
Hom.:
0
Cov.:
31
AF XY:
0.0000403
AC XY:
3
AN XY:
74454
show subpopulations
African (AFR)
AF:
0.0000962
AC:
4
AN:
41568
American (AMR)
AF:
0.00
AC:
0
AN:
15304
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5152
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
292
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.512
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

Genome 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
Alfa
AF:
0.0000283
Hom.:
0
Bravo
AF:
0.0000264

ClinVar

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

Submissions by phenotype

Actin accumulation myopathy Uncertain:1
Jul 31, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change falls in intron 5 of the ACTA1 gene. It does not directly change the encoded amino acid sequence of the ACTA1 protein. It affects a nucleotide within the consensus splice site. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 464131). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.45
CADD
Benign
12
DANN
Benign
0.87
PhyloP100
0.93

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00041
dbscSNV1_RF
Benign
0.046
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: rs200342114; hg19: chr1-229567735; API