ATP1A2

Chr 1ADAR

ATPase Na+/K+ transporting subunit alpha 2

Also known as: DEE98, FARIMPD, FHM2, MHP2

The ATP1A2 gene encodes the alpha-2 subunit of Na+/K+-ATPase, which establishes and maintains electrochemical gradients of sodium and potassium ions across plasma membranes that are essential for neuronal excitability. Heterozygous mutations cause autosomal dominant familial hemiplegic migraine type 2 and alternating hemiplegia of childhood through a gain-of-function mechanism, while biallelic mutations result in autosomal recessive developmental and epileptic encephalopathy and severe fetal akinesia syndromes.

GeneReviewsOMIMResearchSummary from RefSeq, OMIM, UniProt, Mechanism
MultiplemechanismAD/ARLOEUF 0.495 OMIM phenotypes
Clinical SummaryATP1A2
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Gene-Disease Validity (ClinGen)
hemiplegic migraine-developmental and epileptic encephalopathy spectrum · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

2 total gene-disease associations curated

Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.33) despite low pLI — interpret in context.
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GeneReview available — ATP1A2
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Missense constrained — critical functional residues
LoF Constraint
0.49LOEUF
pLI 0.000
Z-score 4.37
OE 0.33 (0.220.49)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
4.77Z-score
OE missense 0.45 (0.410.50)
274 obs / 604.0 exp
Constrained

Highly missense-constrained (top ~0.1%)

Observed / Expected Ratios
LoF OE0.33 (0.220.49)
00.351.4
Missense OE0.45 (0.410.50)
00.61.4
Synonymous OE0.99
01.21.6
LoF obs/exp: 16 / 49.1Missense obs/exp: 274 / 604.0Syn Z: 0.07
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
moderateATP1A2-related epileptic encephalopathyGOFAD
strongATP1A2-related neuronal migration disorder with epilepsyOTHERAR
definitiveATP1A2-related migraine, familial hemiplegicLOFAD
DN
0.80top 10%
GOF
0.82top 10%
LOF
0.2091th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function, dominant-negative 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 · 1 literature citation
DNprediction above median
LOF1 literature citation · LOEUF 0.49

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.

Literature Evidence

GOFIonic leakage underlies a gain-of-function effect of dominant disease mutations affecting diverse P-type ATPasesPMID:24336169
LOFHaploinsufficiency of ATP1A2 encoding the Na+/K+ pump alpha2 subunit associated with familial hemiplegic migraine type 2.PMID:12539047

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

ATP1A2 · protein map & ClinVar variants

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

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
Open Research Assistant →
Key Publications
Landmark & review papers · by relevance
PubMed
Hemiplegic migraine.
de Boer I et al.·Handb Clin Neurol
2024Review
Diagnostic and therapeutic aspects of hemiplegic migraine.
Di Stefano V et al.·J Neurol Neurosurg Psychiatry
2020Review
Familial hemiplegic migraine.
Villar-Martinez MD et al.·Handb Clin Neurol
2024Review
Migraine: Genetic Variants and Clinical Phenotypes.
Rainero I et al.·Curr Med Chem
2019Review
Top 5 results · since 2015Search PubMed ↗