1-229432269-C-T

Position:

chr1-229432269-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_StrongPM2PP5_Moderate

The NM_001100.4(ACTA1):c.616+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,594 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

ACTA1
NM_001100.4 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 7.28

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.14197531 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 1-229432269-C-T is Pathogenic according to our data. Variant chr1-229432269-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 464128.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr1-229432269-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ACTA1	NM_001100.4 linkuse as main transcript	c.616+1G>A		splice_donor_variant, intron_variant		ENST00000366684.7	NP_001091.1	P68133

Ensembl

Gene	Transcript	HGVSc	Effect	TSL	MANE	Protein	UniProt
ACTA1	ENST00000366684.7 linkuse as main transcript	c.616+1G>A	splice_donor_variant, intron_variant	1	NM_001100.4	ENSP00000355645.3	P68133
ACTA1	ENST00000366683.4 linkuse as main transcript	c.616+1G>A	splice_donor_variant, intron_variant	5		ENSP00000355644.4	A6NL76
ACTA1	ENST00000684723.1 linkuse as main transcript	c.481+1G>A	splice_donor_variant, intron_variant			ENSP00000508084.1	A0A804HKV3

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152182

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461412

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727050

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152182

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74338

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Actin accumulation myopathy

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 15, 2017

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in ACTA1 are known to be pathogenic. This particular variant has been reported in the literature in an individual affected with nemaline myopathy (PMID: 19562689). This sequence change affects a donor splice site in intron 4 of the ACTA1 gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.60

BayesDel_noAF

Benign

-0.14

CADD

Pathogenic

DANN

Benign

0.97

Eigen

Pathogenic

0.73

Eigen_PC

Uncertain

0.51

FATHMM_MKL

Pathogenic

0.98

GERP RS

3.5

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.90

SpliceAI score (max)

0.95

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.95

Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over