rs876657743

chr1-236737164-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001103.4(ACTN2):c.826A>G(p.Asn276Asp) variant causes a missense 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. 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. N276I) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 28)
• Consequence: ACTN2 NM_001103.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.32

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.78

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ACTN2	NM_001103.4	c.826A>G	p.Asn276Asp	missense_variant	9/21	ENST00000366578.6
ACTN2	NM_001278343.2	c.826A>G	p.Asn276Asp	missense_variant	9/21
ACTN2	NR_184402.1	n.1198A>G		non_coding_transcript_exon_variant	11/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ACTN2	ENST00000366578.6	c.826A>G	p.Asn276Asp	missense_variant	9/21	1	NM_001103.4	A1

Frequencies

GnomAD3 genomes Cov.: 28

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 28

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jan 14, 2016

The p.Asn276Asp variant in ACTN2 has not been previously reported in individuals with cardiomyopathy and was absent from large population studies. Computational prediction tools and conservation analysis suggest that this variant may impact the protein, though this information is not predictive enough to determine path ogenicity. In summary, the clinical significance of the p.Asn276Asp variant is uncertain. -

Primary familial hypertrophic cardiomyopathy;C2677338:Dilated cardiomyopathy 1AA Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 22, 2022

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. 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 not expected to disrupt ACTN2 protein function. ClinVar contains an entry for this variant (Variation ID: 228436). This variant has not been reported in the literature in individuals affected with ACTN2-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces asparagine, which is neutral and polar, with aspartic acid, which is acidic and polar, at codon 276 of the ACTN2 protein (p.Asn276Asp). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Uncertain	0.045	T
BayesDel_noAF	Benign	-0.17
Cadd	Pathogenic	27
Dann	Uncertain	1.0
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Benign	0.011	T
MetaRNN	Pathogenic	0.78	D;D;D
MetaSVM	Uncertain	-0.16	T
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.88	D
Sift4G	Uncertain	0.015	D;T;T
Polyphen		0.76	.;.;P
Vest4		0.75
MutPred		0.46		.;Loss of MoRF binding (P = 0.1465);Loss of MoRF binding (P = 0.1465);
MVP		0.84
MPC		2.1
ClinPred		0.98	D
GERP RS		6.0
Varity_R		0.87
gMVP		0.87

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs876657743; hg19: chr1-236900464;