chr1-236737120-A-G

Variant names:

• chr1-236737120-A-G
• rs794728964
• NM_001103.4:c.784-2A>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001103.4(ACTN2):​c.784-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 28)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: ACTN2 NM_001103.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.32
• Publications: 1 publications found

Genes affected

ACTN2 (HGNC:164): (actinin alpha 2) Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeletal proteins, including the alpha and beta spectrins and dystrophins. Alpha actinin is an actin-binding protein with multiple roles in different cell types. In nonmuscle cells, the cytoskeletal isoform is found along microfilament bundles and adherens-type junctions, where it is involved in binding actin to the membrane. In contrast, skeletal, cardiac, and smooth muscle isoforms are localized to the Z-disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments. This gene encodes a muscle-specific, alpha actinin isoform that is expressed in both skeletal and cardiac muscles. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2013]

ACTN2 Gene-Disease associations (from GenCC):

• intrinsic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE, MODERATE Submitted by: Laboratory for Molecular Medicine, ClinGen
• myopathy, congenital, with structured cores and z-line abnormalities

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• dilated cardiomyopathy 1AA

  Inheritance: AD Classification: MODERATE, LIMITED Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• heart conduction disease

  Inheritance: AD Classification: LIMITED Submitted by: Genomics England PanelApp
• myopathy, distal, 6, adult-onset, autosomal dominant

  Inheritance: AD, Unknown Classification: LIMITED Submitted by: Broad Center for Mendelian Genomics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.03463687 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5, offset of -31, new splice context is: gtgcgcattcccgtcgacAGagc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001103.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACTN2	NM_001103.4	MANE Select	c.784-2A>G		splice_acceptor intron	N/A	NP_001094.1
	ACTN2	NM_001278343.2		c.784-2A>G		splice_acceptor intron	N/A	NP_001265272.1
	ACTN2	NR_184402.1		n.1156-2A>G		splice_acceptor intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	ACTN2	ENST00000366578.6	TSL:1 MANE Select	c.784-2A>G		splice_acceptor intron	N/A	ENSP00000355537.4
	ACTN2	ENST00000542672.7	TSL:1	c.784-2A>G		splice_acceptor intron	N/A	ENSP00000443495.1
	ACTN2	ENST00000967362.1		c.884A>G	p.Gln295Arg	missense	Exon 9 of 21	ENSP00000637421.1

Frequencies

GnomAD3 genomes Cov.: 28

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1444974 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 718854

African (AFR) AF: 0.00 AC: 0 AN: 33254

American (AMR) AF: 0.00 AC: 0 AN: 44264

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25538

East Asian (EAS) AF: 0.00 AC: 0 AN: 39036

South Asian (SAS) AF: 0.00 AC: 0 AN: 86034

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51408

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5672

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1100488

Other (OTH) AF: 0.00 AC: 0 AN: 59280

GnomAD4 genome Cov.: 28

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	not provided (1)
-	1	-	Primary familial hypertrophic cardiomyopathy;C2677338:Dilated cardiomyopathy 1AA (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		9.3
GERP RS		6.0
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.93		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.93		Position offset: 2

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

Other links and lift over

dbSNP: rs794728964; hg19: chr1-236900420;