1-236731272-G-A

Position:

• chr1-236731272-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001103.4(ACTN2):​c.655G>A​(p.Ala219Thr) 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 (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: ACTN2 NM_001103.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 10.0

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.966

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ACTN2	NM_001103.4	c.655G>A	p.Ala219Thr	missense_variant	7/21	ENST00000366578.6	NP_001094.1
ACTN2	NM_001278343.2	c.655G>A	p.Ala219Thr	missense_variant	7/21		NP_001265272.1
ACTN2	NR_184402.1	n.830G>A		non_coding_transcript_exon_variant	7/23

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ACTN2	ENST00000366578.6	c.655G>A	p.Ala219Thr	missense_variant	7/21	1	NM_001103.4	ENSP00000355537	A1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000342 AC: 5 AN: 1461612 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 727108

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: 0.00000360

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

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

May 02, 2017

The p.Ala219Thr variant in ACTN2 has not been previously reported in individuals with cardiomyopathy or in large population studies. Computational prediction to ols and conservation analysis suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, the clinical significance of the p.Ala219Thr variant is uncertain. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 03, 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 expected to disrupt ACTN2 protein function. ClinVar contains an entry for this variant (Variation ID: 517375). 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 alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 219 of the ACTN2 protein (p.Ala219Thr). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.95	.;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.97	D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Pathogenic	4.5	H;H
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.80	T
PROVEAN	Uncertain	-3.7	D;D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0040	D;D
Sift4G	Pathogenic	0.0010	D;D
Polyphen		1.0	.;D
Vest4		0.88
MutPred		0.86		Gain of catalytic residue at E217 (P = 0.1191);Gain of catalytic residue at E217 (P = 0.1191);
MVP		0.88
MPC		1.9
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.94
gMVP		0.85

Splicing

Name	Calibrated prediction	Score	Prediction
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

LitVar

Other links and lift over

dbSNP: rs1246542277; hg19: chr1-236894572; COSMIC: COSV63978630;