ACTN2

Chr 1AD

actinin alpha 2

Also known as: CMD1AA, CMH23, CMYO8, CMYP8, MPD6, MYOCOZ

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]

GeneReviewsOMIMResearchGenerating clinical summary…
MultiplemechanismADLOEUF 0.244 OMIM phenotypes
Clinical SummaryACTN2
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Gene-Disease Validity (ClinGen)
ACTN2-related cardiac and skeletal myopathy · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 1.00). One damaged copy is likely sufficient to cause disease.
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GeneReview available — ACTN2
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

LoF intolerant — likely haploinsufficient
LoF Constraint?
0.24LOEUF
pLI 1.000
Z-score 5.73
OE 0.12 (0.070.24)
Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint?
1.29Z-score
OE missense 0.84 (0.780.91)
446 obs / 529.7 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.12 (0.070.24)
00.351.4
Missense OE?0.84 (0.780.91)
00.61.4
Synonymous OE?0.97
01.21.6
LoF obs/exp: 6 / 49.6Missense obs/exp: 446 / 529.7Syn Z: 0.33
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveACTN2-related cardiac and skeletal myopathyOTHERAD

This gene — mechanism propensity

DN
0.6164th %ile
GOF
0.78top 25%
LOF
0.4233th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and loss-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

GOFprediction above median
LOFLOEUF 0.24

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

ACTN2 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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