👪

Inheritance

2

Autosomal dominant CACNA1A-related disorder HP:0000006

CACNA1A-related FHM1, EA2, SCA6, and overlapping phenotypes generally follow autosomal dominant inheritance, with variable expressivity and incomplete penetrance across families and subtypes.

Autosomal dominant inheritance Penetrance: INCOMPLETE Expressivity: VARIABLE

Show evidence (2 references)

PMID:20301562 SUPPORT Human Clinical

"FHM and simplex hemiplegic migraine caused by a heterozygous ATP1A2, CACNA1A, PRRT2, or SCN1A pathogenic variant are inherited in an autosomal dominant manner."

GeneReviews supports autosomal dominant inheritance for CACNA1A-related FHM.

PMID:20301319 SUPPORT Human Clinical

"SCA6 is inherited in an autosomal dominant manner."

GeneReviews supports autosomal dominant inheritance for the SCA6 subtype.

De novo CACNA1A epileptic encephalopathy in DEE42 HP:0000006

Severe early-onset CACNA1A developmental and epileptic encephalopathy often presents as a simplex case due to a de novo heterozygous pathogenic variant; recurrence risk is usually low for unaffected parents but is not zero because parental mosaicism has been reported in epileptic encephalopathy cohorts.

Autosomal dominant inheritance Penetrance: UNKNOWN Expressivity: VARIABLE

Show evidence (2 references)

PMID:27476654 SUPPORT Human Clinical

"Our results provide definitive evidence that de novo mutations in SLC1A2 and CACNA1A cause specific EEs and expand the compendium of clinically relevant genotypes for GABRB3."

Supports de novo CACNA1A pathogenic variants as a cause of epileptic encephalopathy.

PMID:27476654 SUPPORT Human Clinical

"parental mosaicism was identified in two out of 14 cases tested with mutant allelic fractions of 5%-6% in the unaffected parents"

Supports recurrence counseling that accounts for parental mosaicism despite apparent de novo disease.

◆

Subtypes

4

Episodic Ataxia Type 2

Caused by loss-of-function variants in CACNA1A. Characterized by recurrent episodes of ataxia lasting hours to days, interictal nystagmus, and progressive cerebellar atrophy. Responsive to acetazolamide.

Show evidence (1 reference)

PMID:36592223 SUPPORT Human Clinical

"The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders."

Confirms EA2 as part of the CACNA1A phenotypic spectrum.

Familial Hemiplegic Migraine Type 1

Caused by gain-of-function missense variants in CACNA1A. Characterized by migraine attacks with reversible motor weakness (hemiplegia), often with visual aura, sensory symptoms, and aphasia.

Show evidence (1 reference)

PMID:36592223 SUPPORT Human Clinical

"The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders."

Confirms FHM1 as part of the CACNA1A phenotypic spectrum.

Spinocerebellar Ataxia Type 6

Caused by small CAG trinucleotide repeat expansions (20-33 repeats) in exon 47 of CACNA1A. Presents as a late-onset, slowly progressive cerebellar ataxia with dysarthria and nystagmus.

Show evidence (1 reference)

PMID:38286873 SUPPORT Human Clinical

"Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease that manifests in midlife and progressively worsens with age."

Confirms SCA6 as a progressive neurodegenerative CACNA1A-related disease.

Developmental and Epileptic Encephalopathy Type 42

Caused by severe gain-of-function or dominant-negative CACNA1A variants. Presents in infancy with refractory seizures, severe developmental delay, and cerebellar dysfunction.

Show evidence (1 reference)

PMID:38681799 SUPPORT Human Clinical

"The broad spectrum of CACNA1A-related neurological disorders includes developmental and epileptic encephalopathies, familial hemiplegic migraine type 1, episodic ataxia type 2, spinocerebellar ataxia type 6, together with unclassified presentations with developmental delay, ataxia, intellectual..."

Confirms DEE as part of the CACNA1A-related disorder spectrum.

⚙

Pathophysiology

5

P/Q-type Calcium Channel Dysfunction

CACNA1A encodes the pore-forming alpha-1A subunit of P/Q-type voltage-gated calcium channels (Cav2.1). These channels are critical for calcium influx at presynaptic nerve terminals, particularly at cerebellar Purkinje cells and granule cell synapses. Pathogenic variants alter channel gating, trafficking, or expression, leading to disrupted neurotransmitter release and cerebellar dysfunction.

Purkinje cell link cerebellar granule cell link

Calcium ion transmembrane transport via voltage-gated calcium channel link Neurotransmitter release link ↕ DYSREGULATED

P/Q-type calcium channel activity link

cerebellum link cerebral cortex link

Downstream

Cortical Spreading Depression in FHM1 GOF variants enhance presynaptic Ca2+ influx, promoting excess glutamate release and CSD susceptibility.

Polyglutamine Aggregation in SCA6 PolyQ expansion in the Cav2.1 C-terminus causes protein misfolding and Purkinje cell degeneration.

Thalamocortical Circuit Disruption in DEE Both GOF and LOF variants disrupt Cav2.1-dependent synaptic transmission in thalamocortical circuits.

Show evidence (2 references)

PMID:38681799 SUPPORT Human Clinical

"This gene encodes the α1 subunit of the P/Q-type calcium channel Cav2.1, which is globally expressed in the brain and crucial for fast synaptic neurotransmission."

Confirms CACNA1A encodes the Cav2.1 P/Q-type calcium channel subunit essential for synaptic transmission.

PMID:36592223 SUPPORT Human Clinical

"In the last decade, variants in the Ca2+ channel gene CACNA1A emerged as a frequent aetiology of rare neurological phenotypes sharing a common denominator of variable paroxysmal manifestations and chronic cerebellar dysfunction."

Confirms that CACNA1A variants cause cerebellar dysfunction through calcium channel disruption.

Cortical Spreading Depression in FHM1

Gain-of-function CACNA1A variants in FHM1 increase P/Q-type channel activity, leading to enhanced glutamate release from cortical pyramidal neurons. This creates a susceptibility to cortical spreading depression, the electrophysiological substrate of migraine aura, and may trigger episodes of hemiplegia through prolonged cortical inhibition.

pyramidal neuron link

Glutamate secretion link ↑ INCREASED Synaptic transmission link ↕ DYSREGULATED

Show evidence (1 reference)

PMID:36592223 SUPPORT Human Clinical

"The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders."

FHM1 with hemiplegic aura is a hallmark paroxysmal feature driven by gain-of-function CACNA1A variants and cortical spreading depression.

Polyglutamine Aggregation in SCA6

SCA6 is caused by expansion of a CAG trinucleotide repeat in CACNA1A exon 47, encoding a polyglutamine tract in the cytoplasmic C-terminal domain of Cav2.1. The expanded polyglutamine tract promotes protein misfolding and aggregation, leading to Purkinje cell degeneration. Unlike other polyglutamine diseases, SCA6 expansions are relatively small (20-33 repeats).

Purkinje cell link

Inclusion body assembly link ↑ INCREASED Purkinje cell degeneration link ↑ INCREASED

Downstream

Mitochondrial Dysfunction in SCA6 Progression Polyglutamine-mediated Purkinje cell stress leads to mitochondrial damage and impaired mitophagy.

Show evidence (1 reference)

PMID:38286873 SUPPORT Human Clinical

"Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease that manifests in midlife and progressively worsens with age."

Confirms SCA6 as a progressive neurodegenerative process caused by CACNA1A polyglutamine expansion.

Mitochondrial Dysfunction in SCA6 Progression

In SCA6, transcriptomic analysis reveals early downregulation of mitochondrial gene expression that precedes functional decline. As disease progresses, mitochondrial membrane potential declines, oxidative stress increases, and mitophagy becomes impaired, creating a feed-forward loop of organellar stress that contributes to Purkinje cell degeneration.

Purkinje cell link

Mitophagy link ↓ DECREASED Oxidative stress response link ↑ INCREASED

Show evidence (3 references)

PMID:38286873 SUPPORT Model Organism

"We explored mitochondrial function and structure and observed that changes in mitochondrial structure preceded changes in function, and that mitochondrial function was not significantly altered at disease onset but was impaired later during disease progression."

Demonstrates that mitochondrial structural changes precede functional decline in SCA6 mouse model.

PMID:38286873 SUPPORT Model Organism

"In addition, we observed impairment in mitophagy that exacerbates mitochondrial dysfunction at late disease stages."

Confirms impaired mitophagy as a contributor to disease progression in SCA6.

PMID:38286873 SUPPORT Human Clinical

"In post-mortem SCA6 patient cerebellar tissue, we observed metabolic changes that are consistent with mitochondrial impairments, supporting our results from animal models being translatable to human disease."

Post-mortem human data supports that mitochondrial dysfunction translates from the animal model to human SCA6.

Thalamocortical Circuit Disruption in DEE

In CACNA1A-related epilepsy and DEE, both gain-of-function and loss-of-function variants disrupt Cav2.1-dependent synaptic transmission in thalamocortical circuits. The spectrum of seizures is broad and includes absence seizures, focal seizures, generalized tonic-clonic seizures, status epilepticus, and infantile spasms. Over half of cases are refractory to current antiseizure medications.

thalamic excitatory neuron link inhibitory interneuron link

Synaptic transmission link

Show evidence (3 references)

PMID:38681799 SUPPORT Human Clinical

"The spectrum of CACNA1A-related seizures is broad across both loss-of-function and gain-of-function variants and includes absence seizures, focal seizures with altered consciousness, generalized tonic-clonic seizures, tonic seizures, status epilepticus, and infantile spasms."

Confirms the broad seizure spectrum across both LOF and GOF variants.

PMID:38681799 SUPPORT Human Clinical

"Furthermore, over half of CACNA1A-related epilepsies are refractory to current therapies."

Confirms the high rate of treatment-refractory epilepsy in CACNA1A-related DEE.

PMID:37555011 SUPPORT Human Clinical

"About 49 (42.20%) patients had controlled seizures while 67 (57.80%) individuals remained with refractory seizures."

Systematic aggregation confirming 57.8% of CACNA1A epilepsy patients have refractory seizures.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

●

Phenotypes

10

Eye 1

Nystagmus VERY_FREQUENT Nystagmus (HP:0000639)

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"Chronic neurological signs encompassed a cerebellar syndrome in 35/41 (85%), which showed almost no progression during the observation period"

Nystagmus is a hallmark component of the chronic cerebellar syndrome seen in 85% of non-polyQ CACNA1A patients.

Nervous System 9

Episodic Ataxia VERY_FREQUENT Episodic ataxia (HP:0002131)

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"Developmental delay and episodic symptoms were the first disease manifestation in 9/41 (22%) and 32/41 (78%) patients respectively."

In the Austrian natural history cohort, episodic symptoms (including ataxia) were the first manifestation in 78% of patients.

Progressive Cerebellar Ataxia FREQUENT Progressive cerebellar ataxia (HP:0002073)

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"Chronic neurological signs encompassed a cerebellar syndrome in 35/41 (85%), which showed almost no progression during the observation period"

85% of patients in the Austrian cohort had a chronic cerebellar syndrome, though progression was minimal during follow-up in non-polyQ cases.

Migraine with Aura FREQUENT Migraine with aura (HP:0002077)

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"Non-polyglutamine CACNA1A variants underlie an extremely variable phenotypic spectrum encompassing developmental delay, hemiplegic migraine, epilepsy, psychiatric symptoms, episodic and chronic cerebellar signs."

Hemiplegic migraine is a key component of the non-polyQ CACNA1A phenotypic spectrum.

Seizures FREQUENT Seizure (HP:0001250)

Show evidence (2 references)

PMID:37555011 SUPPORT Human Clinical

"The epileptic manifestations included status epilepticus (n = 64), provoked seizures (n = 49), focal seizures (n = 37), EE (n = 29), absence seizures (n = 26), and myoclonic seizures (n = 10)."

Systematic review of 130 epileptic patients showing the broad seizure spectrum, with status epilepticus as the most common manifestation.

PMID:37555011 SUPPORT Human Clinical

"Status epilepticus correlated with variants located on S4, S5, and S6 (p = 0.000)."

Genotype-phenotype correlation showing that variant location within channel transmembrane segments predicts status epilepticus risk.

Dysarthria FREQUENT Dysarthria (HP:0001260)

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"Chronic neurological signs encompassed a cerebellar syndrome in 35/41 (85%), which showed almost no progression during the observation period"

Dysarthria is a component of the chronic cerebellar syndrome seen in 85% of patients in the Austrian natural history cohort.

Cerebellar Atrophy FREQUENT Cerebellar atrophy (HP:0001272)

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"Chronic neurological signs encompassed a cerebellar syndrome in 35/41 (85%), which showed almost no progression during the observation period"

Cerebellar atrophy on MRI is a hallmark finding in CACNA1A disease; the Austrian cohort showed chronic cerebellar signs in 85% of patients.

Intellectual Disability FREQUENT Intellectual disability (HP:0001249)

Show evidence (2 references)

PMID:37555011 SUPPORT Human Clinical

"About 187 individuals with GDD/ID harboring 123 variants were found (case series plus data from literature)."

Large systematic aggregation confirming intellectual disability as a prominent feature across CACNA1A variants.

PMID:37555011 SUPPORT Human Clinical

"GOF variants were linked with severe-profound GDD/ID while LOF variants were associated with mild-moderate GDD/ID (p = 0.001)."

Demonstrates genotype-phenotype correlation for intellectual disability severity based on variant functional class.

Cognitive Deficits FREQUENT Cognitive impairment (HP:0100543)

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"cognitive deficits in 9/20 (45%, MOCA test score < 26)"

45% of tested patients in the Austrian non-polyQ cohort had cognitive deficits on standardized testing.

Psychiatric and Behavioral Symptoms OCCASIONAL Atypical behavior (HP:0000708)

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"psychiatric and behavioral symptoms in 11/41(27%)."

Approximately 27% of patients in the Austrian cohort had psychiatric or behavioral symptoms.

🧬

Genetic Associations

1

CACNA1A (Causative)

Autosomal dominant inheritance

Show evidence (2 references)

PMID:38681799 SUPPORT Human Clinical

"To date, almost 1700 CACNA1A variants have been reported in ClinVar, with over 400 listed as Pathogenic or Likely Pathogenic, but with limited-to-no clinical or functional data."

Confirms the large number of known CACNA1A variants and the challenge of variant interpretation.

PMID:39110218 SUPPORT Human Clinical

"We recruited 41 subjects with non-polyglutamine CACNA1A disease, of which 38 (93%) familial cases."

High familial rate (93%) supports autosomal dominant inheritance pattern.

💊

Treatments

6

Acetazolamide

Action: acetazolamide therapy Ontology label: Pharmacotherapy NCIT:C15986

Carbonic anhydrase inhibitor that reduces frequency and severity of episodic ataxia attacks in EA2. In a randomized controlled trial, acetazolamide reduced attacks to 52% compared with placebo.

Show evidence (2 references)

PMID:34484942 SUPPORT Human Clinical

"Compared with placebo, fampridine reduced the number of attacks to 63% (95% CI 54%-74%) and acetazolamide to 52% (95% CI 46%-60%)."

Phase III RCT demonstrating acetazolamide significantly reduces EA2 attack frequency vs placebo.

PMID:39110218 SUPPORT Human Clinical

"At the last visit, 27/41 patients (66%) required an interval prophylaxis (including acetazolamide, flunarizine, 4-aminopyridine, topiramate), which was efficacious in reducing the frequency and severity of episodic symptoms in all cases."

Real-world cohort data confirming efficacy of interval prophylaxis including acetazolamide.

4-Aminopyridine (Fampridine)

Action: 4-aminopyridine therapy Ontology label: Pharmacotherapy NCIT:C15986

Potassium channel blocker that reduces attack frequency in EA2. In a randomized controlled trial, fampridine reduced attacks to 63% compared with placebo, with fewer side effects than acetazolamide.

Show evidence (2 references)

PMID:34484942 SUPPORT Human Clinical

"Compared with placebo, fampridine reduced the number of attacks to 63% (95% CI 54%-74%) and acetazolamide to 52% (95% CI 46%-60%)."

Phase III RCT demonstrating fampridine significantly reduces EA2 attack frequency vs placebo.

PMID:34484942 SUPPORT Human Clinical

"Fampridine 10 mg twice daily had fewer side effects than acetazolamide 250 mg 3 times daily."

Fampridine had a more favorable side effect profile than acetazolamide in the RCT.

Migraine Prophylaxis

Action: migraine prophylaxis Ontology label: Pharmacotherapy NCIT:C15986

Standard migraine preventive medications (e.g., flunarizine, topiramate, valproate) used for FHM1 attack prevention. In one case, the anti-CGRP antibody galcanezumab reduced migraine days from 4 to 1 per month in therapy-resistant hemiplegic migraine.

Show evidence (1 reference)

PMID:39110218 SUPPORT Human Clinical

"In one patient in his 70ies with progressively therapy resistant hemiplegic migraine, treatment with the anti-CGRP antibody galcanezumab successfully reduced the frequency of migraine days from 4 to 1/month."

Case report of galcanezumab efficacy in therapy-resistant CACNA1A-related hemiplegic migraine.

Antiseizure therapy for CACNA1A-related DEE42

Action: anticonvulsant agent therapy MAXO:0000167

Seizures in CACNA1A-related DEE require individualized antiseizure therapy and epilepsy-specialist monitoring. More than half of reported CACNA1A epilepsy cases remain refractory, so treatment response should be tracked closely and care should not assume a single CACNA1A-specific regimen.

Target Phenotypes: Seizures ↗

Show evidence (2 references)

PMID:38681799 SUPPORT Human Clinical

"Furthermore, over half of CACNA1A-related epilepsies are refractory to current therapies."

Supports the need for seizure-directed treatment while noting frequent treatment resistance.

PMID:37555011 SUPPORT Human Clinical

"About 49 (42.20%) patients had controlled seizures while 67 (57.80%) individuals remained with refractory seizures."

Systematic review data quantify refractory seizures in CACNA1A epilepsy.

SCA6 supportive rehabilitation

Action: supportive care MAXO:0000950

SCA6 management is supportive and targets gait ataxia, dysarthria, nystagmus, dysphagia, fall risk, nutrition, and communication. Physical therapy, occupational therapy, speech therapy, walking aids, home adaptations, and symptom-directed medications are used because there is no established disease-modifying therapy.

Target Phenotypes: Progressive cerebellar ataxia ↗ Dysarthria ↗ Nystagmus ↗

Show evidence (2 references)

PMID:20301319 SUPPORT Human Clinical

"physical therapy and exercises enhancing balance and core strength"

GeneReviews supports physical therapy as part of SCA6 supportive management.

PMID:20301319 SUPPORT Human Clinical

"speech therapy and communication devices for dysarthria"

GeneReviews supports speech and communication interventions for SCA6 dysarthria.

Vasoconstrictor and cerebral angiography avoidance in FHM1

Action: medical action avoidance MAXO:0001014

Individuals with CACNA1A-FHM should avoid vasoconstricting agents and unnecessary cerebral angiography because these exposures can increase stroke risk or precipitate severe attacks.

Target Phenotypes: Migraine with aura ↗

Show evidence (1 reference)

PMID:20301562 SUPPORT Human Clinical

"Vasoconstricting agents because of the risk of stroke; cerebral angiography as it may precipitate a severe attack."

GeneReviews identifies these FHM exposures as agents or circumstances to avoid.

{ }

Source YAML

click to show

name: CACNA1A-Related Disorder
creation_date: "2026-03-20T12:00:00Z"
updated_date: "2026-04-06T22:37:07Z"
category: Mendelian
description: >-
  CACNA1A-related disorder is a spectrum of neurological conditions caused by
  pathogenic variants in the CACNA1A gene encoding the alpha-1A subunit of
  P/Q-type voltage-gated calcium channels (Cav2.1). These channels are
  predominantly expressed at presynaptic terminals in the cerebellum and other
  brain regions, where they regulate neurotransmitter release. The phenotypic
  spectrum includes episodic ataxia type 2 (EA2), familial hemiplegic migraine
  type 1 (FHM1), spinocerebellar ataxia type 6 (SCA6), and developmental and
  epileptic encephalopathy type 42 (DEE42). Missense gain-of-function variants
  typically cause FHM1, loss-of-function variants cause EA2, and polyglutamine
  expansions in the C-terminus cause SCA6. Over half of CACNA1A-related
  epilepsies are refractory to current therapies.
disease_term:
  preferred_term: CACNA1A-related disorder
  term:
    id: MONDO:0100254
    label: CACNA1A-related complex neurodevelopmental disorder
parents:
- Channelopathy
- Cerebellar disorder
- Neurodevelopmental disorder
synonyms:
- CACNA1A channelopathy
- P/Q-type calcium channelopathy
has_subtypes:
- name: Episodic Ataxia Type 2
  classification: molecular
  description: >-
    Caused by loss-of-function variants in CACNA1A. Characterized by
    recurrent episodes of ataxia lasting hours to days, interictal nystagmus,
    and progressive cerebellar atrophy. Responsive to acetazolamide.
  evidence:
  - reference: PMID:36592223
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders."
    explanation: Confirms EA2 as part of the CACNA1A phenotypic spectrum.
- name: Familial Hemiplegic Migraine Type 1
  classification: molecular
  description: >-
    Caused by gain-of-function missense variants in CACNA1A. Characterized by
    migraine attacks with reversible motor weakness (hemiplegia), often with
    visual aura, sensory symptoms, and aphasia.
  evidence:
  - reference: PMID:36592223
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders."
    explanation: Confirms FHM1 as part of the CACNA1A phenotypic spectrum.
- name: Spinocerebellar Ataxia Type 6
  classification: molecular
  description: >-
    Caused by small CAG trinucleotide repeat expansions (20-33 repeats) in
    exon 47 of CACNA1A. Presents as a late-onset, slowly progressive
    cerebellar ataxia with dysarthria and nystagmus.
  evidence:
  - reference: PMID:38286873
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease that manifests in midlife and progressively worsens with age."
    explanation: Confirms SCA6 as a progressive neurodegenerative CACNA1A-related disease.
- name: Developmental and Epileptic Encephalopathy Type 42
  classification: molecular
  description: >-
    Caused by severe gain-of-function or dominant-negative CACNA1A variants.
    Presents in infancy with refractory seizures, severe developmental delay,
    and cerebellar dysfunction.
  evidence:
  - reference: PMID:38681799
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The broad spectrum of CACNA1A-related neurological disorders includes developmental and epileptic encephalopathies, familial hemiplegic migraine type 1, episodic ataxia type 2, spinocerebellar ataxia type 6, together with unclassified presentations with developmental delay, ataxia, intellectual disability, autism spectrum disorder, and language impairment."
    explanation: Confirms DEE as part of the CACNA1A-related disorder spectrum.
prevalence:
- subtype: Episodic Ataxia Type 2
  population: Global reported populations
  percentage: Unknown
  notes: >-
    A stable population prevalence for the full CACNA1A-related spectrum has
    not been established because it spans several allelic disorders. Within
    the spectrum, episodic ataxia type 2 is consistently described as a rare
    neurological disorder.
  evidence:
  - reference: PMID:17395137
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Episodic ataxia type 2 (EA 2) is a rare neurological disorder of autosomal dominant inheritance resulting from dysfunction of a voltage-gated calcium channel."
    explanation: >-
      This review supports rarity for the best-defined CACNA1A subtype while
      noting that spectrum-wide prevalence remains unsettled.
inheritance:
- name: Autosomal dominant CACNA1A-related disorder
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  penetrance: INCOMPLETE
  expressivity: VARIABLE
  description: >-
    CACNA1A-related FHM1, EA2, SCA6, and overlapping phenotypes generally follow
    autosomal dominant inheritance, with variable expressivity and incomplete
    penetrance across families and subtypes.
  evidence:
  - reference: PMID:20301562
    reference_title: "Familial Hemiplegic Migraine."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "FHM and simplex hemiplegic migraine caused by a heterozygous ATP1A2, CACNA1A, PRRT2, or SCN1A pathogenic variant are inherited in an autosomal dominant manner."
    explanation: GeneReviews supports autosomal dominant inheritance for CACNA1A-related FHM.
  - reference: PMID:20301319
    reference_title: "Spinocerebellar Ataxia Type 6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "SCA6 is inherited in an autosomal dominant manner."
    explanation: GeneReviews supports autosomal dominant inheritance for the SCA6 subtype.
- name: De novo CACNA1A epileptic encephalopathy in DEE42
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  penetrance: UNKNOWN
  expressivity: VARIABLE
  description: >-
    Severe early-onset CACNA1A developmental and epileptic encephalopathy often
    presents as a simplex case due to a de novo heterozygous pathogenic variant;
    recurrence risk is usually low for unaffected parents but is not zero
    because parental mosaicism has been reported in epileptic encephalopathy
    cohorts.
  evidence:
  - reference: PMID:27476654
    reference_title: "De Novo Mutations in SLC1A2 and CACNA1A Are Important Causes of Epileptic Encephalopathies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Our results provide definitive evidence that de novo mutations in SLC1A2 and CACNA1A cause specific EEs and expand the compendium of clinically relevant genotypes for GABRB3."
    explanation: Supports de novo CACNA1A pathogenic variants as a cause of epileptic encephalopathy.
  - reference: PMID:27476654
    reference_title: "De Novo Mutations in SLC1A2 and CACNA1A Are Important Causes of Epileptic Encephalopathies."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "parental mosaicism was identified in two out of 14 cases tested with mutant allelic fractions of 5%-6% in the unaffected parents"
    explanation: Supports recurrence counseling that accounts for parental mosaicism despite apparent de novo disease.
pathophysiology:
- name: P/Q-type Calcium Channel Dysfunction
  description: >-
    CACNA1A encodes the pore-forming alpha-1A subunit of P/Q-type
    voltage-gated calcium channels (Cav2.1). These channels are critical for
    calcium influx at presynaptic nerve terminals, particularly at cerebellar
    Purkinje cells and granule cell synapses. Pathogenic variants alter
    channel gating, trafficking, or expression, leading to disrupted
    neurotransmitter release and cerebellar dysfunction.
  gene:
    preferred_term: CACNA1A
    term:
      id: hgnc:1388
      label: CACNA1A
  molecular_functions:
  - preferred_term: P/Q-type calcium channel activity
    term:
      id: GO:0008331
      label: high voltage-gated calcium channel activity
  cell_types:
  - preferred_term: Purkinje cell
    term:
      id: CL:0000121
      label: Purkinje cell
  - preferred_term: cerebellar granule cell
    term:
      id: CL:0001031
      label: cerebellar granule cell
  biological_processes:
  - preferred_term: Calcium ion transmembrane transport via voltage-gated calcium channel
    term:
      id: GO:0061577
      label: calcium ion transmembrane transport via high voltage-gated calcium channel
  - preferred_term: Neurotransmitter release
    term:
      id: GO:0007269
      label: neurotransmitter secretion
    modifier: DYSREGULATED
  downstream:
  - target: Cortical Spreading Depression in FHM1
    description: GOF variants enhance presynaptic Ca2+ influx, promoting excess glutamate release and CSD susceptibility.
  - target: Polyglutamine Aggregation in SCA6
    description: PolyQ expansion in the Cav2.1 C-terminus causes protein misfolding and Purkinje cell degeneration.
  - target: Thalamocortical Circuit Disruption in DEE
    description: Both GOF and LOF variants disrupt Cav2.1-dependent synaptic transmission in thalamocortical circuits.
  locations:
  - preferred_term: cerebellum
    term:
      id: UBERON:0002037
      label: cerebellum
  - preferred_term: cerebral cortex
    term:
      id: UBERON:0000956
      label: cerebral cortex
  evidence:
  - reference: PMID:38681799
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This gene encodes the α1 subunit of the P/Q-type calcium channel Cav2.1, which is globally expressed in the brain and crucial for fast synaptic neurotransmission."
    explanation: Confirms CACNA1A encodes the Cav2.1 P/Q-type calcium channel subunit essential for synaptic transmission.
  - reference: PMID:36592223
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In the last decade, variants in the Ca2+ channel gene CACNA1A emerged as a frequent aetiology of rare neurological phenotypes sharing a common denominator of variable paroxysmal manifestations and chronic cerebellar dysfunction."
    explanation: Confirms that CACNA1A variants cause cerebellar dysfunction through calcium channel disruption.
- name: Cortical Spreading Depression in FHM1
  description: >-
    Gain-of-function CACNA1A variants in FHM1 increase P/Q-type channel
    activity, leading to enhanced glutamate release from cortical pyramidal
    neurons. This creates a susceptibility to cortical spreading depression,
    the electrophysiological substrate of migraine aura, and may trigger
    episodes of hemiplegia through prolonged cortical inhibition.
  cell_types:
  - preferred_term: pyramidal neuron
    term:
      id: CL:0000598
      label: pyramidal neuron
  biological_processes:
  - preferred_term: Glutamate secretion
    term:
      id: GO:0014047
      label: glutamate secretion
    modifier: INCREASED
  - preferred_term: Synaptic transmission
    term:
      id: GO:0007268
      label: chemical synaptic transmission
    modifier: DYSREGULATED
  evidence:
  - reference: PMID:36592223
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders."
    explanation: FHM1 with hemiplegic aura is a hallmark paroxysmal feature driven by gain-of-function CACNA1A variants and cortical spreading depression.
- name: Polyglutamine Aggregation in SCA6
  description: >-
    SCA6 is caused by expansion of a CAG trinucleotide repeat in CACNA1A
    exon 47, encoding a polyglutamine tract in the cytoplasmic C-terminal
    domain of Cav2.1. The expanded polyglutamine tract promotes protein
    misfolding and aggregation, leading to Purkinje cell degeneration.
    Unlike other polyglutamine diseases, SCA6 expansions are relatively
    small (20-33 repeats).
  cell_types:
  - preferred_term: Purkinje cell
    term:
      id: CL:0000121
      label: Purkinje cell
  biological_processes:
  - preferred_term: Inclusion body assembly
    term:
      id: GO:0070841
      label: inclusion body assembly
    modifier: INCREASED
  - preferred_term: Purkinje cell degeneration
    term:
      id: GO:0008219
      label: cell death
    modifier: INCREASED
  downstream:
  - target: Mitochondrial Dysfunction in SCA6 Progression
    description: Polyglutamine-mediated Purkinje cell stress leads to mitochondrial damage and impaired mitophagy.
  evidence:
  - reference: PMID:38286873
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease that manifests in midlife and progressively worsens with age."
    explanation: Confirms SCA6 as a progressive neurodegenerative process caused by CACNA1A polyglutamine expansion.
- name: Mitochondrial Dysfunction in SCA6 Progression
  description: >-
    In SCA6, transcriptomic analysis reveals early downregulation of
    mitochondrial gene expression that precedes functional decline.
    As disease progresses, mitochondrial membrane potential declines,
    oxidative stress increases, and mitophagy becomes impaired,
    creating a feed-forward loop of organellar stress that contributes
    to Purkinje cell degeneration.
  cell_types:
  - preferred_term: Purkinje cell
    term:
      id: CL:0000121
      label: Purkinje cell
  biological_processes:
  - preferred_term: Mitophagy
    term:
      id: GO:0000422
      label: autophagy of mitochondrion
    modifier: DECREASED
  - preferred_term: Oxidative stress response
    term:
      id: GO:0006979
      label: response to oxidative stress
    modifier: INCREASED
  evidence:
  - reference: PMID:38286873
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "We explored mitochondrial function and structure and observed that changes in mitochondrial structure preceded changes in function, and that mitochondrial function was not significantly altered at disease onset but was impaired later during disease progression."
    explanation: Demonstrates that mitochondrial structural changes precede functional decline in SCA6 mouse model.
  - reference: PMID:38286873
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "In addition, we observed impairment in mitophagy that exacerbates mitochondrial dysfunction at late disease stages."
    explanation: Confirms impaired mitophagy as a contributor to disease progression in SCA6.
  - reference: PMID:38286873
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In post-mortem SCA6 patient cerebellar tissue, we observed metabolic changes that are consistent with mitochondrial impairments, supporting our results from animal models being translatable to human disease."
    explanation: Post-mortem human data supports that mitochondrial dysfunction translates from the animal model to human SCA6.
- name: Thalamocortical Circuit Disruption in DEE
  description: >-
    In CACNA1A-related epilepsy and DEE, both gain-of-function and
    loss-of-function variants disrupt Cav2.1-dependent synaptic transmission
    in thalamocortical circuits. The spectrum of seizures is broad and includes
    absence seizures, focal seizures, generalized tonic-clonic seizures,
    status epilepticus, and infantile spasms. Over half of cases are
    refractory to current antiseizure medications.
  cell_types:
  - preferred_term: thalamic excitatory neuron
    term:
      id: CL:4023068
      label: thalamic excitatory neuron
  - preferred_term: inhibitory interneuron
    term:
      id: CL:0000498
      label: inhibitory interneuron
  biological_processes:
  - preferred_term: Synaptic transmission
    term:
      id: GO:0007268
      label: chemical synaptic transmission
  evidence:
  - reference: PMID:38681799
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The spectrum of CACNA1A-related seizures is broad across both loss-of-function and gain-of-function variants and includes absence seizures, focal seizures with altered consciousness, generalized tonic-clonic seizures, tonic seizures, status epilepticus, and infantile spasms."
    explanation: Confirms the broad seizure spectrum across both LOF and GOF variants.
  - reference: PMID:38681799
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Furthermore, over half of CACNA1A-related epilepsies are refractory to current therapies."
    explanation: Confirms the high rate of treatment-refractory epilepsy in CACNA1A-related DEE.
  - reference: PMID:37555011
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "About 49 (42.20%) patients had controlled seizures while 67 (57.80%) individuals remained with refractory seizures."
    explanation: Systematic aggregation confirming 57.8% of CACNA1A epilepsy patients have refractory seizures.
phenotypes:
- category: Neurological
  name: Episodic Ataxia
  subtype: Episodic Ataxia Type 2
  frequency: VERY_FREQUENT
  description: >-
    Recurrent attacks of cerebellar ataxia lasting minutes to days,
    triggered by stress, exertion, or startle. Cardinal feature of EA2.
  phenotype_term:
    preferred_term: Episodic ataxia
    term:
      id: HP:0002131
      label: Episodic ataxia
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Developmental delay and episodic symptoms were the first disease manifestation in 9/41 (22%) and 32/41 (78%) patients respectively."
    explanation: In the Austrian natural history cohort, episodic symptoms (including ataxia) were the first manifestation in 78% of patients.
- category: Neurological
  name: Progressive Cerebellar Ataxia
  subtypes:
  - Episodic Ataxia Type 2
  - Spinocerebellar Ataxia Type 6
  frequency: FREQUENT
  description: >-
    Slowly progressive gait and limb ataxia, predominant in SCA6 and
    developing in some EA2 patients over time.
  phenotype_term:
    preferred_term: Progressive cerebellar ataxia
    term:
      id: HP:0002073
      label: Progressive cerebellar ataxia
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chronic neurological signs encompassed a cerebellar syndrome in 35/41 (85%), which showed almost no progression during the observation period"
    explanation: 85% of patients in the Austrian cohort had a chronic cerebellar syndrome, though progression was minimal during follow-up in non-polyQ cases.
- category: Neurological
  name: Nystagmus
  subtypes:
  - Episodic Ataxia Type 2
  - Spinocerebellar Ataxia Type 6
  frequency: VERY_FREQUENT
  description: >-
    Involuntary rhythmic eye movements, often downbeat nystagmus,
    present in EA2 and SCA6. May persist between episodes in EA2.
  phenotype_term:
    preferred_term: Nystagmus
    term:
      id: HP:0000639
      label: Nystagmus
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chronic neurological signs encompassed a cerebellar syndrome in 35/41 (85%), which showed almost no progression during the observation period"
    explanation: Nystagmus is a hallmark component of the chronic cerebellar syndrome seen in 85% of non-polyQ CACNA1A patients.
- category: Neurological
  name: Migraine with Aura
  subtype: Familial Hemiplegic Migraine Type 1
  frequency: FREQUENT
  description: >-
    Migraine attacks preceded by visual or sensory aura, characteristic
    of FHM1. May be accompanied by transient hemiplegia.
  phenotype_term:
    preferred_term: Migraine with aura
    term:
      id: HP:0002077
      label: Migraine with aura
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Non-polyglutamine CACNA1A variants underlie an extremely variable phenotypic spectrum encompassing developmental delay, hemiplegic migraine, epilepsy, psychiatric symptoms, episodic and chronic cerebellar signs."
    explanation: Hemiplegic migraine is a key component of the non-polyQ CACNA1A phenotypic spectrum.
- category: Neurological
  name: Seizures
  subtype: Developmental and Epileptic Encephalopathy Type 42
  frequency: FREQUENT
  description: >-
    Epileptic seizures, particularly prominent in DEE42 but also occurring
    in some EA2 and FHM1 patients. Status epilepticus is the most common
    epileptic manifestation, correlating with gain-of-function variants
    located on S4, S5, and S6 domains.
  phenotype_term:
    preferred_term: Seizures
    term:
      id: HP:0001250
      label: Seizure
  evidence:
  - reference: PMID:37555011
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The epileptic manifestations included status epilepticus (n = 64), provoked seizures (n = 49), focal seizures (n = 37), EE (n = 29), absence seizures (n = 26), and myoclonic seizures (n = 10)."
    explanation: Systematic review of 130 epileptic patients showing the broad seizure spectrum, with status epilepticus as the most common manifestation.
  - reference: PMID:37555011
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Status epilepticus correlated with variants located on S4, S5, and S6 (p = 0.000)."
    explanation: Genotype-phenotype correlation showing that variant location within channel transmembrane segments predicts status epilepticus risk.
- category: Neurological
  name: Dysarthria
  subtype: Spinocerebellar Ataxia Type 6
  frequency: FREQUENT
  description: >-
    Slurred speech due to cerebellar dysfunction, prominent in SCA6
    and during EA2 episodes.
  phenotype_term:
    preferred_term: Dysarthria
    term:
      id: HP:0001260
      label: Dysarthria
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chronic neurological signs encompassed a cerebellar syndrome in 35/41 (85%), which showed almost no progression during the observation period"
    explanation: Dysarthria is a component of the chronic cerebellar syndrome seen in 85% of patients in the Austrian natural history cohort.
- category: Neurological
  name: Cerebellar Atrophy
  subtypes:
  - Episodic Ataxia Type 2
  - Spinocerebellar Ataxia Type 6
  frequency: FREQUENT
  description: >-
    Progressive cerebellar vermis atrophy on MRI, seen in SCA6 and
    long-standing EA2.
  phenotype_term:
    preferred_term: Cerebellar atrophy
    term:
      id: HP:0001272
      label: Cerebellar atrophy
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Chronic neurological signs encompassed a cerebellar syndrome in 35/41 (85%), which showed almost no progression during the observation period"
    explanation: Cerebellar atrophy on MRI is a hallmark finding in CACNA1A disease; the Austrian cohort showed chronic cerebellar signs in 85% of patients.
- category: Neurological
  name: Intellectual Disability
  subtype: Developmental and Epileptic Encephalopathy Type 42
  frequency: FREQUENT
  description: >-
    Cognitive impairment, particularly severe in DEE42 with global
    developmental delay. GOF variants are linked with severe-profound
    GDD/ID while LOF variants are associated with mild-moderate GDD/ID.
  phenotype_term:
    preferred_term: Intellectual disability
    term:
      id: HP:0001249
      label: Intellectual disability
  evidence:
  - reference: PMID:37555011
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "About 187 individuals with GDD/ID harboring 123 variants were found (case series plus data from literature)."
    explanation: Large systematic aggregation confirming intellectual disability as a prominent feature across CACNA1A variants.
  - reference: PMID:37555011
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "GOF variants were linked with severe-profound GDD/ID while LOF variants were associated with mild-moderate GDD/ID (p = 0.001)."
    explanation: Demonstrates genotype-phenotype correlation for intellectual disability severity based on variant functional class.
- category: Neurological
  name: Cognitive Deficits
  subtypes:
  - Episodic Ataxia Type 2
  - Familial Hemiplegic Migraine Type 1
  - Developmental and Epileptic Encephalopathy Type 42
  frequency: FREQUENT
  description: >-
    Cognitive impairment including executive dysfunction, occurring
    in a substantial proportion of patients beyond the DEE subtype.
  phenotype_term:
    preferred_term: Cognitive impairment
    term:
      id: HP:0100543
      label: Cognitive impairment
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "cognitive deficits in 9/20 (45%, MOCA test score < 26)"
    explanation: 45% of tested patients in the Austrian non-polyQ cohort had cognitive deficits on standardized testing.
- category: Neurological
  name: Psychiatric and Behavioral Symptoms
  subtypes:
  - Episodic Ataxia Type 2
  - Familial Hemiplegic Migraine Type 1
  - Developmental and Epileptic Encephalopathy Type 42
  frequency: OCCASIONAL
  description: >-
    Psychiatric and behavioral symptoms including mood disorders, anxiety,
    and behavioral disturbances, occurring in approximately 27% of patients.
  phenotype_term:
    preferred_term: Behavioral abnormality
    term:
      id: HP:0000708
      label: Atypical behavior
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "psychiatric and behavioral symptoms in 11/41(27%)."
    explanation: Approximately 27% of patients in the Austrian cohort had psychiatric or behavioral symptoms.
genetic:
- name: CACNA1A
  association: Causative
  inheritance:
  - name: Autosomal dominant inheritance
    inheritance_term:
      preferred_term: Autosomal dominant
      term:
        id: HP:0000006
        label: Autosomal dominant inheritance
    penetrance: INCOMPLETE
    expressivity: VARIABLE
    evidence:
    - reference: PMID:39110218
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "We recruited 41 subjects with non-polyglutamine CACNA1A disease, of which 38 (93%) familial cases."
      explanation: 93% familial rate strongly supports autosomal dominant inheritance.
  variants:
  - name: Loss-of-function variants (EA2)
    description: >-
      Truncating, splice-site, and missense variants causing loss of
      channel function. Over 100 pathogenic variants described. LOF variants
      are associated with absence seizures and mild-moderate GDD/ID.
    clinical_significance: PATHOGENIC
    evidence:
    - reference: PMID:37555011
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "LOF variants were associated with absence seizures (p = 0.000)."
      explanation: Confirms genotype-phenotype correlation for LOF variants and absence seizures.
  - name: Gain-of-function missense variants (FHM1)
    description: >-
      Missense variants (e.g., R192Q, S218L) that increase channel open
      probability or shift voltage dependence of activation. GOF variants
      are linked with severe-profound GDD/ID and status epilepticus.
    clinical_significance: PATHOGENIC
    evidence:
    - reference: PMID:37555011
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Status epilepticus was linked with GOF variants (p = 0.000)."
      explanation: Confirms that GOF variants predispose to the most severe epileptic manifestation.
  - name: CAG repeat expansion (SCA6)
    description: >-
      Expansion of CAG repeat in exon 47 from normal (4-18) to pathogenic
      (20-33 repeats). Smallest known pathogenic trinucleotide expansion.
    clinical_significance: PATHOGENIC
    evidence:
    - reference: PMID:38286873
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease that manifests in midlife and progressively worsens with age."
      explanation: Confirms SCA6 as a CAG-repeat-driven progressive neurodegenerative disease.
  gene_term:
    preferred_term: CACNA1A
    term:
      id: hgnc:1388
      label: CACNA1A
  evidence:
  - reference: PMID:38681799
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "To date, almost 1700 CACNA1A variants have been reported in ClinVar, with over 400 listed as Pathogenic or Likely Pathogenic, but with limited-to-no clinical or functional data."
    explanation: Confirms the large number of known CACNA1A variants and the challenge of variant interpretation.
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "We recruited 41 subjects with non-polyglutamine CACNA1A disease, of which 38 (93%) familial cases."
    explanation: High familial rate (93%) supports autosomal dominant inheritance pattern.
diagnosis:
- name: CACNA1A molecular diagnosis and subtype assignment
  description: >-
    Molecular testing confirms non-repeat CACNA1A-related disease by identifying
    a heterozygous pathogenic CACNA1A variant in a person with a compatible
    hemiplegic migraine, episodic ataxia, epilepsy, developmental, or overlapping
    neurologic presentation. The clinical subtype is assigned from the variant
    class plus the neurologic phenotype.
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: MAXO:0000533
      label: molecular genetic testing
  evidence:
  - reference: PMID:20301562
    reference_title: "Familial Hemiplegic Migraine."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The molecular diagnosis can be established in a proband by identification of a heterozygous pathogenic variant in ATP1A2, CACNA1A, PRRT2, or SCN1A."
    explanation: GeneReviews supports CACNA1A heterozygous variant identification as diagnostic in FHM-spectrum presentations.
  - reference: PMID:38681799
    reference_title: "Developing a pathway to clinical trials for CACNA1A-related epilepsies: A patient organization perspective."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The broad spectrum of CACNA1A-related neurological disorders includes developmental and epileptic encephalopathies, familial hemiplegic migraine type 1, episodic ataxia type 2, spinocerebellar ataxia type 6, together with unclassified presentations with developmental delay, ataxia, intellectual disability, autism spectrum disorder, and language impairment."
    explanation: >-
      Defines the CACNA1A-related disorder spectrum that the molecular diagnosis resolves into specific clinical entities.
- name: SCA6 CAG repeat expansion testing
  description: >-
    Suspected SCA6 requires CACNA1A CAG trinucleotide repeat expansion analysis;
    standard sequence-focused panels can miss repeat expansions, so the testing
    method must explicitly measure the CACNA1A repeat.
  diagnosis_term:
    preferred_term: molecular genetic testing
    term:
      id: MAXO:0000533
      label: molecular genetic testing
  evidence:
  - reference: PMID:20301319
    reference_title: "Spinocerebellar Ataxia Type 6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The diagnosis of SCA6 rests on the use of molecular genetic testing to detect an abnormal CAG trinucleotide repeat expansion in CACNA1A."
    explanation: GeneReviews explicitly identifies CACNA1A CAG-repeat testing as the diagnostic method for SCA6.
  - reference: PMID:20301319
    reference_title: "Spinocerebellar Ataxia Type 6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Affected individuals have 20 to 33 CAG repeats."
    explanation: Provides the pathogenic repeat-size range used in SCA6 diagnosis.
- name: Neurologic and hemiplegic migraine clinical assessment
  description: >-
    Clinical assessment classifies the presenting syndrome, including hemiplegic
    migraine criteria, episodic or progressive cerebellar signs, developmental
    delay, and seizure history. This assessment guides selection of CACNA1A
    sequencing, repeat-expansion testing, or broader hemiplegic migraine and
    episodic ataxia panels.
  diagnosis_term:
    preferred_term: clinical assessment
    term:
      id: MAXO:0000487
      label: clinical assessment
  evidence:
  - reference: PMID:20301562
    reference_title: "Familial Hemiplegic Migraine."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The clinical diagnosis of FHM can be established in a proband: (1) who fulfills criteria for migraine with aura; (2) in whom the aura includes fully reversible motor weakness and visual, sensory, or language symptoms; and (3) who has at least one first- or second-degree relative with similar attacks that fulfill the diagnostic criteria for hemiplegic migraine."
    explanation: GeneReviews provides clinical diagnostic criteria for the FHM1 branch of the CACNA1A spectrum.
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Non-polyglutamine CACNA1A variants underlie an extremely variable phenotypic spectrum encompassing developmental delay, hemiplegic migraine, epilepsy, psychiatric symptoms, episodic and chronic cerebellar signs."
    explanation: Supports neurologic assessment across non-polyglutamine CACNA1A phenotypes.
- name: Brain MRI for cerebellar atrophy and structural phenotyping
  description: >-
    Brain MRI is used during diagnostic workup to document cerebellar atrophy
    and to phenotype FHM1, EA2, SCA6, and overlapping presentations; normal or
    nonspecific MRI does not exclude CACNA1A disease, especially early in the
    course.
  diagnosis_term:
    preferred_term: magnetic resonance imaging procedure
    term:
      id: MAXO:0000424
      label: magnetic resonance imaging procedure
  evidence:
  - reference: PMID:33544220
    reference_title: "The electrophysiological footprint of CACNA1A disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brain MR imaging was performed within the routine workup either at a 1.5 or 3 T scanner."
    explanation: Supports MRI as part of routine CACNA1A clinical workup in a genetically confirmed cohort.
  - reference: PMID:33544220
    reference_title: "The electrophysiological footprint of CACNA1A disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In 35 cases (92%), cerebellar atrophy was evident."
    explanation: Supports MRI assessment for cerebellar atrophy in CACNA1A disorders.
- name: EEG and phenocopy evaluation for seizure or early-onset presentations
  description: >-
    EEG is appropriate when seizures, developmental and epileptic encephalopathy,
    early-onset disease, or attack-related impaired awareness are suspected.
    EEG findings are not diagnostic alone but can support CACNA1A testing and
    help distinguish CACNA1A-positive disease from phenocopies.
  diagnosis_term:
    preferred_term: electroencephalography
    term:
      id: MAXO:0000932
      label: electroencephalography
  evidence:
  - reference: PMID:33544220
    reference_title: "The electrophysiological footprint of CACNA1A disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "EEG is applied to study their episodic manifestations, but findings in the intervals did not gain attention up to date."
    explanation: Supports EEG as a diagnostic workup tool for episodic CACNA1A manifestations.
  - reference: PMID:33544220
    reference_title: "The electrophysiological footprint of CACNA1A disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "EEG abnormalities between attacks are highly prevalent in episodic CACNA1A disorders and especially associated with younger age at examination and earlier disease onset."
    explanation: Supports EEG use in early-onset and severe episodic presentations.
  - reference: PMID:33544220
    reference_title: "The electrophysiological footprint of CACNA1A disorders."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "EEG findings in CACNA1A-negative phenocopies (n = 15) were largely unremarkable (p = 0.03 in the comparison with CACNA1A patients)."
    explanation: Supports EEG as part of a phenocopy-aware differential workup.
treatments:
- name: Acetazolamide
  description: >-
    Carbonic anhydrase inhibitor that reduces frequency and severity of
    episodic ataxia attacks in EA2. In a randomized controlled trial,
    acetazolamide reduced attacks to 52% compared with placebo.
  treatment_term:
    preferred_term: acetazolamide therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  evidence:
  - reference: PMID:34484942
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Compared with placebo, fampridine reduced the number of attacks to 63% (95% CI 54%-74%) and acetazolamide to 52% (95% CI 46%-60%)."
    explanation: Phase III RCT demonstrating acetazolamide significantly reduces EA2 attack frequency vs placebo.
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "At the last visit, 27/41 patients (66%) required an interval prophylaxis (including acetazolamide, flunarizine, 4-aminopyridine, topiramate), which was efficacious in reducing the frequency and severity of episodic symptoms in all cases."
    explanation: Real-world cohort data confirming efficacy of interval prophylaxis including acetazolamide.
- name: 4-Aminopyridine (Fampridine)
  description: >-
    Potassium channel blocker that reduces attack frequency in EA2.
    In a randomized controlled trial, fampridine reduced attacks to 63%
    compared with placebo, with fewer side effects than acetazolamide.
  treatment_term:
    preferred_term: 4-aminopyridine therapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  evidence:
  - reference: PMID:34484942
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Compared with placebo, fampridine reduced the number of attacks to 63% (95% CI 54%-74%) and acetazolamide to 52% (95% CI 46%-60%)."
    explanation: Phase III RCT demonstrating fampridine significantly reduces EA2 attack frequency vs placebo.
  - reference: PMID:34484942
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Fampridine 10 mg twice daily had fewer side effects than acetazolamide 250 mg 3 times daily."
    explanation: Fampridine had a more favorable side effect profile than acetazolamide in the RCT.
- name: Migraine Prophylaxis
  description: >-
    Standard migraine preventive medications (e.g., flunarizine, topiramate,
    valproate) used for FHM1 attack prevention. In one case, the anti-CGRP
    antibody galcanezumab reduced migraine days from 4 to 1 per month in
    therapy-resistant hemiplegic migraine.
  treatment_term:
    preferred_term: migraine prophylaxis
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  evidence:
  - reference: PMID:39110218
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In one patient in his 70ies with progressively therapy resistant hemiplegic migraine, treatment with the anti-CGRP antibody galcanezumab successfully reduced the frequency of migraine days from 4 to 1/month."
    explanation: Case report of galcanezumab efficacy in therapy-resistant CACNA1A-related hemiplegic migraine.
- name: Antiseizure therapy for CACNA1A-related DEE42
  description: >-
    Seizures in CACNA1A-related DEE require individualized antiseizure therapy
    and epilepsy-specialist monitoring. More than half of reported CACNA1A
    epilepsy cases remain refractory, so treatment response should be tracked
    closely and care should not assume a single CACNA1A-specific regimen.
  treatment_term:
    preferred_term: anticonvulsant agent therapy
    term:
      id: MAXO:0000167
      label: anticonvulsant agent therapy
  target_phenotypes:
  - preferred_term: Seizures
    term:
      id: HP:0001250
      label: Seizure
  evidence:
  - reference: PMID:38681799
    reference_title: "Developing a pathway to clinical trials for CACNA1A-related epilepsies: A patient organization perspective."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Furthermore, over half of CACNA1A-related epilepsies are refractory to current therapies."
    explanation: Supports the need for seizure-directed treatment while noting frequent treatment resistance.
  - reference: PMID:37555011
    reference_title: "The genotype-phenotype correlations of the CACNA1A-related neurodevelopmental disorders: a small case series and literature reviews."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "About 49 (42.20%) patients had controlled seizures while 67 (57.80%) individuals remained with refractory seizures."
    explanation: Systematic review data quantify refractory seizures in CACNA1A epilepsy.
- name: SCA6 supportive rehabilitation
  description: >-
    SCA6 management is supportive and targets gait ataxia, dysarthria,
    nystagmus, dysphagia, fall risk, nutrition, and communication. Physical
    therapy, occupational therapy, speech therapy, walking aids, home
    adaptations, and symptom-directed medications are used because there is no
    established disease-modifying therapy.
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
  target_phenotypes:
  - preferred_term: Progressive cerebellar ataxia
    term:
      id: HP:0002073
      label: Progressive cerebellar ataxia
  - preferred_term: Dysarthria
    term:
      id: HP:0001260
      label: Dysarthria
  - preferred_term: Nystagmus
    term:
      id: HP:0000639
      label: Nystagmus
  evidence:
  - reference: PMID:20301319
    reference_title: "Spinocerebellar Ataxia Type 6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "physical therapy and exercises enhancing balance and core strength"
    explanation: GeneReviews supports physical therapy as part of SCA6 supportive management.
  - reference: PMID:20301319
    reference_title: "Spinocerebellar Ataxia Type 6."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "speech therapy and communication devices for dysarthria"
    explanation: GeneReviews supports speech and communication interventions for SCA6 dysarthria.
- name: Vasoconstrictor and cerebral angiography avoidance in FHM1
  description: >-
    Individuals with CACNA1A-FHM should avoid vasoconstricting agents and
    unnecessary cerebral angiography because these exposures can increase stroke
    risk or precipitate severe attacks.
  treatment_term:
    preferred_term: medical action avoidance
    term:
      id: MAXO:0001014
      label: medical action avoidance
  target_phenotypes:
  - preferred_term: Migraine with aura
    term:
      id: HP:0002077
      label: Migraine with aura
  evidence:
  - reference: PMID:20301562
    reference_title: "Familial Hemiplegic Migraine."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Vasoconstricting agents because of the risk of stroke; cerebral angiography as it may precipitate a severe attack."
    explanation: GeneReviews identifies these FHM exposures as agents or circumstances to avoid.
references:
- reference: PMID:20301562
  title: "Familial Hemiplegic Migraine."
  tags:
  - GeneReviews
  findings: []
- reference: PMID:20301319
  title: "Spinocerebellar Ataxia Type 6."
  tags:
  - GeneReviews
  findings: []
- reference: PMID:27476654
  title: "De Novo Mutations in SLC1A2 and CACNA1A Are Important Causes of Epileptic Encephalopathies."
  findings: []
- reference: PMID:33544220
  title: "The electrophysiological footprint of CACNA1A disorders."
  findings: []
datasets: []

📚

References & Deep Research

References

4

PMID:20301562

Familial Hemiplegic Migraine.

No top-level findings curated for this source.

PMID:20301319

Spinocerebellar Ataxia Type 6.

No top-level findings curated for this source.

PMID:27476654

De Novo Mutations in SLC1A2 and CACNA1A Are Important Causes of Epileptic Encephalopathies.

No top-level findings curated for this source.

PMID:33544220

The electrophysiological footprint of CACNA1A disorders.

No top-level findings curated for this source.

Deep Research

1

Falcon ▸

Disease Pathophysiology Research Template

Edison Scientific Literature 32 citations 2026-03-20T13:27:52.800430

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Pathophysiology Research Template

Target Disease

Disease Name: CACNA1A-Related Disorder
MONDO ID: (if available)
Category: Mendelian

Research Objectives

Please provide a comprehensive research report on the pathophysiology of CACNA1A-Related Disorder. Focus on the molecular and cellular mechanisms underlying disease progression.

Required Information

1. Core Pathophysiology

What are the primary pathophysiological mechanisms?
What molecular pathways are dysregulated?
What cellular processes are affected?

2. Key Molecular Players

Genes/Proteins: Which genes are causally involved or implicated?
Chemical Entities: What metabolites, drugs, or small molecules are relevant?
Cell Types: Which cell types are primarily affected?
Anatomical Locations: Which tissues/organs are involved?

3. Biological Processes (for GO annotation)

What biological processes (GO terms) are disrupted?
Consider: signaling pathways, metabolic processes, cellular responses, transport, etc.

4. Cellular Components

Where in the cell do key processes occur?
Consider: organelles, membrane compartments, extracellular space, etc.

5. Disease Progression

What is the sequence of events from initial trigger to clinical manifestation?
Are there distinct stages or phases?

6. Phenotypic Manifestations

What are the key clinical phenotypes?
How do they relate to the underlying mechanisms?

Citation Requirements

Cite primary literature (PMID preferred) for all mechanistic claims
Prioritize recent reviews and landmark papers
Include direct quotes where possible to support key statements

Output Format

Structure your response as a narrative that could be used to populate a disease knowledge base entry with: - Pathophysiology description - Gene/protein annotations with ontology terms (HGNC, GO) - Phenotype associations (HP terms) - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Evidence items with PMIDs

Comprehensive Research Report: Pathophysiology of CACNA1A-Related Disorder (Mendelian)

Scope and nomenclature

“CACNA1A-related disorder” is an umbrella term for a spectrum of allelic neurologic channelopathies caused by pathogenic variants in CACNA1A, including (classically) episodic ataxia type 2 (EA2), familial/sporadic hemiplegic migraine type 1 (FHM1/SHM1), developmental and epileptic encephalopathy (DEE42) and broader neurodevelopmental disorders (NDD), and spinocerebellar ataxia type 6 (SCA6; polyQ expansion) (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7, indelicato2023cacna1arelatedchannelopathiesclinical pages 7-9).

Key definition (molecular): CACNA1A encodes the pore-forming α1A subunit of the P/Q-type (CaV2.1) voltage-gated calcium channel (VGCC) (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4).

Primary functional concept: At presynaptic terminals, depolarization opens CaV2.1 channels, permitting Ca2+ influx that “triggers the vesicular neurotransmitter release”; CaV2.1 Ca2+ currents also influence “the gating of K+ channels, transcriptional activity as well as intracellular signalling pathways” (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4).

Key recent 2023–2024 reviews and translational perspectives include Indelicato & Boesch (2023; https://doi.org/10.1007/164_2022_625) (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4), Szymanowicz et al. (May 2024; https://doi.org/10.3390/diseases12050090) (szymanowicz2024areviewof pages 8-9), and Fox et al. (Jan 2024; https://doi.org/10.1177/26330040241245725) (fox2024developingapathway pages 1-2).

1) Core pathophysiology (molecular → cellular → systems)

1.1 Presynaptic calcium entry and synaptic transmission dysfunction

Across the CACNA1A spectrum, a unifying mechanism is disturbed CaV2.1-dependent presynaptic Ca2+ entry that perturbs neurotransmitter release and circuit stability (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, kessi2023thegenotype–phenotypecorrelations pages 1-2). CaV2.1 is described as abundant in cerebellar circuitry (notably Purkinje and granule layers) and present across multiple forebrain structures; one review explicitly places CaV2.1 in presynaptic regions of cortex, thalamus, hypothalamus, hippocampus, and cerebellum (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, szymanowicz2024areviewof pages 3-4, fox2024developingapathway pages 2-3).

1.2 Gain-of-function (GOF) vs loss-of-function (LOF) as a central organizing principle

A major current framework stratifies CACNA1A variants by net electrophysiologic effect:

FHM1/SHM1 is typically driven by GOF missense variants that increase CaV2.1 opening and presynaptic Ca2+ influx, enhancing glutamatergic transmission and shifting excitation/inhibition balance (szymanowicz2024areviewof pages 8-9).
EA2 is typically driven by LOF variants (often truncating or deletions) that reduce channel function and impair cerebellar signaling (szymanowicz2024areviewof pages 11-12, indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7).
DEE/NDD can result from both GOF and LOF missense variants, including trafficking-dominant-negative LOF variants, with genotype–phenotype correlations emerging (kessi2023thegenotype–phenotypecorrelations pages 1-2, fox2024developingapathway pages 3-5).
SCA6 is caused by a C-terminal polyglutamine (CAG) expansion in CACNA1A and shows prominent degenerative pathology with additional downstream bioenergetic/mitochondrial contributions (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, leung2024mitochondrialdamageand pages 1-2).

1.3 Migraine pathophysiology: cortical spreading depression (CSD)

Recent syntheses link CaV2.1 GOF to CSD propensity via enhanced presynaptic Ca2+ influx at active zones and increased glutamate release. Szymanowicz et al. (2024) describe FHM1-associated changes such as activation at more negative potentials and prolonged open times, increasing calcium influx in presynaptic terminals/active zones and promoting “elevated glutamate release,” such that “The increase in excitatory synaptic activity leads to cortical spreading depression (CSD)” (https://doi.org/10.3390/diseases12050090) (szymanowicz2024areviewof pages 8-9). Indelicato & Boesch (2023) similarly state that FHM1 GOF mutations increase Ca2+ currents and “facilitate a cascade of events that results in cortical spreading depression” (https://doi.org/10.1007/164_2022_625) (indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7).

1.4 Epilepsy/DEE pathophysiology: thalamocortical and inhibitory circuit failure

Fox et al. (2024) emphasize that Cav2.1 is “crucial for fast synaptic neurotransmission” and link absence epilepsy mechanisms to thalamocortical circuitry disturbances including “reduced synaptic release from layer VI pyramidal neurons projecting to the thalamus,” “increased thalamic excitability,” and “enhanced cortical and limbic excitability due to failure of synaptic release from GABAergic interneurons” (https://doi.org/10.1177/26330040241245725) (fox2024developingapathway pages 1-2, fox2024developingapathway pages 3-5). This places CACNA1A disease mechanisms at the intersection of excitatory drive, thalamic bursting, and impaired inhibition.

1.5 SCA6 degeneration and organelle stress: mitochondria and impaired mitophagy as progression modifiers

A major 2024 advance is a disease-stage-resolved, mechanism-focused study of SCA6 showing that transcriptomic mitochondrial signatures precede physiological decline, and that impaired mitochondrial quality control emerges with progression.

Leung et al. (Acta Neuropathologica, Jan 2024; https://doi.org/10.1007/s00401-023-02680-z) report that at disease onset “changes in mitochondrial structure preceded changes in function,” with mitochondrial membrane potential “normal at disease onset but impaired later during disease progression” (leung2024mitochondrialdamageand pages 1-2). They further report increasing oxidative stress later in disease (“increase in oxidative stress in cerebellar Purkinje cells at later disease stages although not at disease onset”) and evidence of impaired mitophagy (“a reduction of markers of both autophagosomes and mitophagosomes”), concluding a “progressive reduction in mitophagy” that likely exacerbates mitochondrial dysfunction (leung2024mitochondrialdamageand pages 1-2). Importantly, pathology was not restricted to Purkinje cells (“not limited to cerebellar Purkinje cells but … also observed in molecular layer interneurons”) (leung2024mitochondrialdamageand pages 1-2).

2) Key molecular players, pathways, cell types, and anatomy

2.1 Genes/proteins (HGNC/UniProt-style annotations)

CACNA1A (HGNC: “calcium voltage-gated channel subunit alpha1 A”; protein: CaV2.1 α1A pore-forming subunit) (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, fox2024developingapathway pages 2-3).
α1ACT: Kessi et al. note CACNA1A also encodes α1ACT, described as a transcription factor, supporting gene-regulatory contributions beyond ion flux (kessi2023thegenotype–phenotypecorrelations pages 1-2).

2.2 Dysregulated molecular pathways / cellular processes (GO-oriented)

Evidence-supported disrupted processes include: - Voltage-gated calcium channel activity / depolarization-induced Ca2+ influx (szymanowicz2024areviewof pages 3-4). - Synaptic vesicle exocytosis / neurotransmitter release (direct quote: “triggers the vesicular neurotransmitter release”) (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4). - Chemical synaptic transmission and synaptic plasticity (szymanowicz2024areviewof pages 3-4, kessi2023thegenotype–phenotypecorrelations pages 1-2). - Regulation of membrane potential / neuronal excitability, including E/I imbalance favoring excitation in migraine models (szymanowicz2024areviewof pages 8-9). - Regulation of gene expression/transcription and intracellular signaling pathways (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, fox2024developingapathway pages 2-3). - For SCA6 progression: mitochondrial organization and function, oxidative stress response, autophagy/mitophagy (supported by downregulated mitochondrial GO terms and mitophagy marker reductions) (leung2024mitochondrialdamageand pages 1-2, leung2024mitochondrialdamageand pages 5-8).

2.3 Cell types (CL-oriented)

Primary implicated cell types (with strongest direct evidence in retrieved sources): - Cerebellar Purkinje cell (key expression site; key degenerative cell type in SCA6 mitochondrial/oxidative stress findings) (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, leung2024mitochondrialdamageand pages 1-2). - Cerebellar granule cell / granule layer neurons (high expression emphasized in review) (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4). - Corticothalamic layer VI pyramidal neurons (absence epilepsy mechanism via reduced synaptic release to thalamus) (fox2024developingapathway pages 3-5). - GABAergic interneurons (failure of inhibitory synaptic release contributing to hyperexcitability) (fox2024developingapathway pages 3-5). - Molecular layer interneurons (SCA6 progression: oxidative stress/mitochondrial dysfunction not limited to Purkinje cells) (leung2024mitochondrialdamageand pages 1-2).

2.4 Anatomical locations (UBERON-oriented)

Cerebellum (including vermis); CACNA1A enrichment and cerebellar phenotypes across EA2/SCA6/NDD (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, szymanowicz2024areviewof pages 15-16).
Cerebral cortex, hippocampus, thalamus, striatum (broad expression and presynaptic localization used to explain epilepsy/migraine and cognitive/psychiatric features) (szymanowicz2024areviewof pages 3-4, fox2024developingapathway pages 2-3).

2.5 Chemical entities (CHEBI-oriented; clinically relevant)

Acetazolamide (carbonic anhydrase inhibitor; classic EA2 prophylaxis; also used broadly across episodic CACNA1A symptoms) (szymanowicz2024areviewof pages 11-12, muth2021fampridineandacetazolamide pages 1-2).
Fampridine / 4-aminopyridine (4-AP) (K+ channel blocker; used for EA2 and related episodic symptoms; supported by RCT evidence) (muth2021fampridineandacetazolamide pages 1-2).
Flunarizine, topiramate (used as interval prophylaxis in natural history cohort) (indelicato2024naturalhistoryof pages 1-2).
Galcanezumab (anti-CGRP monoclonal antibody; reported in a patient with therapy-resistant hemiplegic migraine) (indelicato2024naturalhistoryof pages 1-2).

3) Cellular components (subcellular localization)

The best-supported subcellular localization across sources is presynaptic: - Indelicato & Boesch (2023) explicitly localize function to the “presynaptic terminal,” where Ca2+ entry triggers vesicular neurotransmitter release (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4). - Szymanowicz et al. (2024) describe presynaptic “active zones of nerve endings” and increased presynaptic terminal Ca2+ influx in FHM1 GOF contexts (szymanowicz2024areviewof pages 8-9).

For SCA6 progression, implicated compartments include: - Mitochondria (structure/function decline over time) (leung2024mitochondrialdamageand pages 1-2). - Autophagosome/mitophagosome–lysosome pathway (marker reductions consistent with impaired mitophagy) (leung2024mitochondrialdamageand pages 1-2).

4) Disease progression model (sequence of events)

A unifying model can be expressed as a variant class → circuit dysfunction → clinical phenotype framework, with additional progressive organelle stress in degenerative SCA6:

Primary trigger: pathogenic CACNA1A variant causes altered CaV2.1 channel biophysics/abundance (LOF, GOF, or polyQ). (indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7, indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4)
Immediate cellular consequence: altered depolarization-evoked presynaptic Ca2+ influx (szymanowicz2024areviewof pages 3-4) changes neurotransmitter release (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4) and network excitability.
Circuit-level consequence:
Migraine: increased excitatory synaptic transmission and CSD susceptibility (szymanowicz2024areviewof pages 8-9).
Epilepsy: thalamocortical release failure and inhibitory interneuron release failure → thalamic hyperexcitability and generalized seizure propensity (fox2024developingapathway pages 3-5).
Ataxia: cerebellar microcircuit dysfunction (Purkinje/granule), producing episodic/chronic cerebellar syndrome (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, szymanowicz2024areviewof pages 11-12).
Progression/degeneration (especially SCA6): mitochondrial gene expression changes at onset, then later decline in mitochondrial membrane potential, rising oxidative stress, and impaired mitophagy that may accelerate late-stage cellular failure (leung2024mitochondrialdamageand pages 1-2, leung2024mitochondrialdamageand pages 5-8).

5) Phenotypic manifestations (HP-oriented), linked to mechanisms

Core phenotypes across the CACNA1A spectrum include: - Episodic ataxia / vertigo (EA2), chronic gait ataxia, nystagmus, dysarthria—consistent with cerebellar circuit dysfunction (indelicato2024naturalhistoryof pages 2-4). - Hemiplegic migraine (FHM1/SHM1), with aura and severe attacks consistent with GOF-driven CSD susceptibility (indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7, szymanowicz2024areviewof pages 8-9). - Epilepsy and DEE: febrile-triggered status epilepticus and seizure heterogeneity reflecting thalamocortical/interneuron release failures and variant-specific gating/trafficking changes (indelicato2023cacna1arelatedchannelopathiesclinical pages 7-9, fox2024developingapathway pages 3-5). - Neurodevelopmental delay/intellectual disability/autism spectrum in subsets, consistent with widespread circuit dysfunction and gene-regulatory roles (kessi2023thegenotype–phenotypecorrelations pages 1-2, fox2024developingapathway pages 2-3).

Quantitative epilepsy/NDD statistics (systematic aggregation through Feb 2023): Kessi et al. compiled 130 epilepsy patients (83 variants) and found status epilepticus (n=64) as the most common manifestation; 57.80% (67/116 with seizure outcome data) remained refractory and 42.20% (49/116) had controlled seizures (https://doi.org/10.3389/fnmol.2023.1222321) (kessi2023thegenotype–phenotypecorrelations pages 1-2).

6) Recent developments (2023–2024) and “latest research” highlights

6.1 Precision phenotyping and genotype–phenotype correlations

A key 2023 step is the explicit linking of GOF vs LOF to distinct neurodevelopmental and epilepsy outcomes: GOF variants associate with severe–profound GDD/ID and status epilepticus; LOF variants associate with milder GDD/ID and absence seizures, and variant topography (S4–S6) correlates with status epilepticus (kessi2023thegenotype–phenotypecorrelations pages 1-2).

6.2 Trial-readiness infrastructure (real-world implementation of translational pipelines)

Fox et al. (2024) quantify the variant interpretation problem (“almost 1700 CACNA1A variants… reported in ClinVar, with over 400… Pathogenic or Likely Pathogenic, but with limited-to-no clinical or functional data”) and emphasize unmet need (“over half of CACNA1A-related epilepsies are refractory to current therapies”) (fox2024developingapathway pages 1-2). They describe real-world implementation of a translational ecosystem: patient-derived iPSCs, multiple animal models, natural history studies, and a global research network >60 scientists/clinicians (fox2024developingapathway pages 1-2, fox2024developingapathway pages 5-7).

6.3 Mechanistic progression biology in SCA6

Leung et al. (2024) provide a stage-specific mechanistic map in SCA6 linking early transcriptomic mitochondrial signatures with later oxidative stress and mitophagy impairment, motivating mitochondria/autophagy pathways as therapeutic target axes, particularly later in disease (leung2024mitochondrialdamageand pages 1-2, leung2024mitochondrialdamageand pages 5-8).

7) Current applications and real-world implementations

7.1 Symptom-targeted pharmacotherapy (implemented clinically)

EA2 treatment evidence (randomized Phase III crossover RCT): Muth et al. (Neurology Clinical Practice, Aug 2021; https://doi.org/10.1212/cpj.0000000000001017) randomized 30 EA2 patients to fampridine, acetazolamide, and placebo in a double-blind, double-dummy crossover. Compared with placebo, fampridine reduced attacks to 63% (95% CI 54–74%) and acetazolamide to 52% (95% CI 46–60%); fampridine had fewer side effects than acetazolamide (muth2021fampridineandacetazolamide pages 1-2). This remains one of the highest-quality quantitative treatment datasets for episodic CACNA1A symptoms.

Natural history cohort implementation (2004–2024, Austria): In a prospective single-center cohort of 41 subjects with non-polyQ CACNA1A variants (Journal of Neurology, Aug 2024; https://doi.org/10.1007/s00415-024-12602-y), 66% (27/41) used interval prophylaxis (acetazolamide, flunarizine, 4-aminopyridine, topiramate), reported as efficacious at reducing episodic symptom burden; a single older patient’s resistant hemiplegic migraine improved with galcanezumab (migraine days 4→1/month) (indelicato2024naturalhistoryof pages 1-2).

7.2 Diagnostics and monitoring

Genetic diagnostics: reviews emphasize broad CACNA1A phenotypes spanning paroxysmal and chronic features; this supports use of exome/panel testing beyond “classic” EA2/FHM1 presentations (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4).
Natural history datasets: the Austrian cohort provides granular symptom frequencies and age-at-onset patterns, useful for endpoint selection and counseling (indelicato2024naturalhistoryof pages 2-4). Visual summaries appear in the paper’s Table/Figure (indelicato2024naturalhistoryof media 9fb4e801, indelicato2024naturalhistoryof media 5d2f1b14, indelicato2024naturalhistoryof media cc87ae80).

8) Relevant statistics and data (recent cohorts)

8.1 2024 Austrian non-polyQ CACNA1A natural history cohort

Indelicato et al. (Aug 2024; https://doi.org/10.1007/s00415-024-12602-y) report: - n=41 genetically confirmed non-polyQ CACNA1A; 93% familial; mean age at first exam 35±22 years (indelicato2024naturalhistoryof pages 1-2). - Onset in childhood/adolescence: 31/41 (76%) (indelicato2024naturalhistoryof pages 1-2). - Initial manifestation: episodic symptoms 32/41 (78%); developmental delay 9/41 (22%) (indelicato2024naturalhistoryof pages 1-2). - Chronic cerebellar syndrome: 35/41 (85%) (indelicato2024naturalhistoryof pages 1-2). - Cerebellar atrophy: 30/36 imaged (83%) (indelicato2024naturalhistoryof pages 2-4). - Episodic symptom examples and frequencies include speech disturbance 28/40 (70%), gait instability 25/40 (63%), headache 25/40 (63%) (indelicato2024naturalhistoryof pages 2-4).

These distributions are also summarized visually in the paper’s table/figure extracts (indelicato2024naturalhistoryof media 9fb4e801, indelicato2024naturalhistoryof media cc87ae80).

8.2 2023 systematic aggregation for CACNA1A-related neurodevelopmental phenotypes

Kessi et al. (Jul 2023; https://doi.org/10.3389/fnmol.2023.1222321) report: - ~187 individuals with GDD/ID (123 variants); GOF variants correlate with severe–profound GDD/ID (p=0.001) (kessi2023thegenotype–phenotypecorrelations pages 1-2). - Among epilepsy cases with reported outcomes, 57.80% refractory (67/116) (kessi2023thegenotype–phenotypecorrelations pages 1-2).

9) Expert opinions and analysis (authoritative perspectives)

Mechanism-to-therapy framing (channelopathy): Indelicato & Boesch (2023) frame CACNA1A disorders as “channelopathies” with genotype-dependent effects (GOF vs LOF vs polyQ), explicitly tying CaV2.1 presynaptic Ca2+ entry to neurotransmitter release and intracellular signaling, and linking GOF to CSD (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7).
Translational gap assessment: Fox et al. (2024) argue that despite a large ClinVar variant space and high refractory epilepsy burden, “current therapies… are primarily symptomatic and do not target disease-specific mechanisms,” motivating genotype-stratified development and clinical trial readiness (fox2024developingapathway pages 2-3).
Progression biology insight: Leung et al. (2024) conclude that mitochondrial dysfunction and impaired mitochondrial degradation likely contribute to progression in SCA6, which is a shift from purely channel-centric models toward combined channel/organellar stress models for late disease stages (leung2024mitochondrialdamageand pages 1-2).

Knowledge-base-ready structured annotations

A) Pathophysiology description (narrative)

CACNA1A-related disorders arise from pathogenic variants in CACNA1A, which encodes the presynaptic P/Q-type CaV2.1 calcium channel α1A subunit. CaV2.1-mediated Ca2+ influx at presynaptic terminals triggers vesicular neurotransmitter release and influences potassium channel gating, transcription, and intracellular signaling. Variant class determines net excitability: GOF variants enhance presynaptic Ca2+ entry and excitatory transmission, promoting CSD and hemiplegic migraine; LOF variants reduce CaV2.1 function, predisposing to episodic cerebellar dysfunction (EA2) and certain seizure phenotypes (e.g., absence). In DEE/NDD, both GOF and LOF disrupt thalamocortical and inhibitory circuits, producing seizure refractoriness and developmental impairment. In SCA6, a C-terminal polyQ expansion is associated with Purkinje-centered degeneration, where early mitochondrial transcriptomic changes precede later mitochondrial functional decline, oxidative stress, and impaired mitophagy that likely contribute to disease progression.

B) Gene/protein annotations (example GO mappings; names provided for GO curation)

CACNA1A / CaV2.1: voltage-gated calcium channel activity, presynaptic calcium ion influx, synaptic vesicle exocytosis, chemical synaptic transmission, synaptic plasticity, regulation of membrane potential/neuronal excitability, transcription/gene regulation (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, kessi2023thegenotype–phenotypecorrelations pages 1-2, fox2024developingapathway pages 2-3).
SCA6 progression modifiers: mitochondrial organization, mitochondrial membrane potential, reactive oxygen species/oxidative stress response, mitophagy/autophagy (leung2024mitochondrialdamageand pages 1-2, leung2024mitochondrialdamageand pages 5-8).

C) Cell type involvement (CL term suggestions)

Purkinje cell; granule cell; cortical pyramidal neuron (layer VI corticothalamic); GABAergic interneuron; thalamic relay neuron; cerebellar molecular layer interneuron (leung2024mitochondrialdamageand pages 1-2, fox2024developingapathway pages 3-5, indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4).

D) Anatomical locations (UBERON term suggestions)

Cerebellum (incl. vermis), cerebral cortex, hippocampus, thalamus, striatum (szymanowicz2024areviewof pages 3-4, fox2024developingapathway pages 2-3, szymanowicz2024areviewof pages 15-16).

E) Chemical entities (CHEBI term suggestions)

Acetazolamide; 4-aminopyridine/fampridine; flunarizine; topiramate; galcanezumab (muth2021fampridineandacetazolamide pages 1-2, indelicato2024naturalhistoryof pages 1-2).

F) Evidence items (with identifiers present in retrieved sources)

Indelicato & Boesch. CACNA1A-Related Channelopathies: Clinical Manifestations and Treatment Options (Jan 2023). DOI/URL: https://doi.org/10.1007/164_2022_625 (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4).
Fox et al. Developing a pathway to clinical trials for CACNA1A-related epilepsies (Jan 2024). DOI/URL: https://doi.org/10.1177/26330040241245725 (fox2024developingapathway pages 1-2).
Indelicato et al. Natural history of non-polyglutamine CACNA1A disease in Austria (Aug 2024). DOI/URL: https://doi.org/10.1007/s00415-024-12602-y (indelicato2024naturalhistoryof pages 1-2).
Leung et al. Mitochondrial damage and impaired mitophagy contribute to disease progression in SCA6 (Jan 2024). DOI/URL: https://doi.org/10.1007/s00401-023-02680-z (leung2024mitochondrialdamageand pages 1-2).

Note on PMID availability: Several mechanistic summaries in the retrieved 2023–2024 sources do not display PMIDs in the provided excerpts; therefore, this report cites DOIs/URLs for those sources. Where PMIDs are required for downstream curation, the DOI-cited papers can be used as index sources to backfill PMIDs from PubMed.

Summary table (mechanism-centric)

Phenotype group	Typical variant class	Core mechanism	Key affected cells/tissues	Key citations with DOI and quoted phrases
EA2	Usually loss-of-function variants, especially truncating/nonsense/frameshift/deletions; reduced CaV2.1/P/Q-channel activity	Reduced presynaptic Ca2+ influx impairs vesicular neurotransmitter release and cerebellar signaling; chronic cerebellar dysfunction likely reflects impaired Purkinje-cell pacemaking/network output. Review evidence states P/Q-channel activation “triggers the vesicular neurotransmitter release,” and EA2 “typically arises from loss-of-function” CACNA1A variants.	Purkinje cells, granule cells; cerebellar cortex/vermian circuitry; broader CNS presynaptic terminals	Indelicato & Boesch 2023, Handb Exp Pharmacol, DOI: https://doi.org/10.1007/164_2022_625 — “triggers the vesicular neurotransmitter release” and EA2 linked to LOF variants (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4, indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7); Szymanowicz et al. 2024, Diseases, DOI: https://doi.org/10.3390/diseases12050090 — EA2 “typically arises from loss-of-function” and CaV2.1 is highly expressed in Purkinje/granule neurons (szymanowicz2024areviewof pages 11-12)
FHM1 / SHM1	Predominantly gain-of-function missense variants (classic examples include R192Q, T666M, S218L)	Increased channel opening probability / activation at more negative potentials / prolonged open time increases presynaptic Ca2+ influx, promotes excess glutamate release, shifts excitation over inhibition, and lowers threshold for cortical spreading depression (CSD). Review evidence: GOF changes “facilitate a cascade of events that results in cortical spreading depression.”	Cerebral cortex, presynaptic excitatory terminals, cortical interneuron/excitatory balance networks; cerebellum may also be involved in overlap phenotypes	Szymanowicz et al. 2024, Diseases, DOI: https://doi.org/10.3390/diseases12050090 — FHM1 variants increase opening probability/negative activation and promote glutamate release/CSD (szymanowicz2024areviewof pages 8-9, szymanowicz2024areviewof pages 3-4); Indelicato & Boesch 2023, DOI: https://doi.org/10.1007/164_2022_625 — FHM1 due to missense GOF mutations that “facilitate a cascade of events that results in cortical spreading depression” (indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7); Schaare et al. 2023, Genes, DOI: https://doi.org/10.3390/genes14020400 — GOF variants may increase hyperexcitability and lower the threshold for CSD (schaare2023concomitantcalciumchannelopathies pages 2-3)
DEE / NDD	Both GOF and LOF missense variants; some severe cases from dominant-negative trafficking-defective LOF; rare biallelic LOF can cause very severe early-onset DEE	Disrupted CaV2.1-dependent synaptic transmission and neuronal excitability; disease mechanisms include reduced synaptic release in corticothalamic pathways, increased thalamic excitability, failure of GABAergic inhibitory release, and broader disturbance of network synchronization/neurodevelopment. GOF tends to associate with more severe GDD/ID and status epilepticus; LOF more with absence seizures.	Corticothalamic layer VI pyramidal neurons, thalamic relay circuits, GABAergic interneurons, cortex/hippocampus/cerebellum; developing neuronal networks	Kessi et al. 2023, Front Mol Neurosci, DOI: https://doi.org/10.3389/fnmol.2023.1222321 — GOF associated with severe–profound GDD/ID and status epilepticus; LOF with milder GDD/ID and absence seizures (kessi2023thegenotype–phenotypecorrelations pages 1-2); Fox et al. 2024, Ther Adv Rare Dis, DOI: https://doi.org/10.1177/26330040241245725 — Cav2.1 is “crucial for fast synaptic neurotransmission”; mechanisms include “reduced synaptic release from layer VI pyramidal neurons projecting to the thalamus,” “increased thalamic excitability,” and impaired GABAergic release (fox2024developingapathway pages 1-2, fox2024developingapathway pages 2-3, fox2024developingapathway pages 3-5)
SCA6	C-terminal polyglutamine (CAG) expansion in CACNA1A	Progressive cerebellar degeneration centered on Purkinje-cell dysfunction; early transcriptomic downregulation of mitochondrial pathways, then later decline in mitochondrial membrane potential, increased oxidative stress, and impaired mitophagy. Key conclusion: “changes in mitochondrial structure preceded changes in function” and “mitochondrial dysfunction and impaired mitochondrial degradation likely contribute to disease progression in SCA6.”	Purkinje cells primarily; also molecular layer interneurons and granule layer/cerebellar vermis; mitochondria/autophagosome-lysosome compartments	Indelicato & Boesch 2023, DOI: https://doi.org/10.1007/164_2022_625 — SCA6 genotype is a CAG polyglutamine expansion in CACNA1A (indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4); Leung et al. 2024, Acta Neuropathologica, DOI: https://doi.org/10.1007/s00401-023-02680-z — “changes in mitochondrial structure preceded changes in function,” oxidative stress rises later, and “mitochondrial dysfunction and impaired mitochondrial degradation likely contribute to disease progression in SCA6” (leung2024mitochondrialdamageand pages 1-2, leung2024pathologicalchangesin pages 32-36, leung2024pathologicalchangesin pages 49-53, leung2024mitochondrialdamageand pages 5-8)

Table: This table summarizes the main CACNA1A-related phenotype groups, their usual variant classes, core molecular/cellular mechanisms, and the principal affected cells and tissues. It is useful as a compact knowledge-base-ready overview linking genotype class to disease mechanism with source-backed citations.

Visual evidence (recent cohort phenotype frequencies)

The Austrian natural history cohort’s individual therapy exposures and phenotype frequency distributions are summarized in the extracted Table/Figure images (indelicato2024naturalhistoryof media 9fb4e801, indelicato2024naturalhistoryof media cc87ae80).

References

(indelicato2023cacna1arelatedchannelopathiesclinical pages 1-4): Elisabetta Indelicato and Sylvia Boesch. Cacna1a-related channelopathies: clinical manifestations and treatment options. Handbook of experimental pharmacology, pages 227-248, Jan 2023. URL: https://doi.org/10.1007/164_2022_625, doi:10.1007/164_2022_625. This article has 24 citations and is from a peer-reviewed journal.
(indelicato2023cacna1arelatedchannelopathiesclinical pages 4-7): Elisabetta Indelicato and Sylvia Boesch. Cacna1a-related channelopathies: clinical manifestations and treatment options. Handbook of experimental pharmacology, pages 227-248, Jan 2023. URL: https://doi.org/10.1007/164_2022_625, doi:10.1007/164_2022_625. This article has 24 citations and is from a peer-reviewed journal.
(indelicato2023cacna1arelatedchannelopathiesclinical pages 7-9): Elisabetta Indelicato and Sylvia Boesch. Cacna1a-related channelopathies: clinical manifestations and treatment options. Handbook of experimental pharmacology, pages 227-248, Jan 2023. URL: https://doi.org/10.1007/164_2022_625, doi:10.1007/164_2022_625. This article has 24 citations and is from a peer-reviewed journal.
(szymanowicz2024areviewof pages 8-9): Oliwia Szymanowicz, Artur Drużdż, Bartosz Słowikowski, Sandra Pawlak, Ewelina Potocka, Ulyana Goutor, Mateusz Konieczny, Małgorzata Ciastoń, Aleksandra Lewandowska, Paweł P. Jagodziński, Wojciech Kozubski, and Jolanta Dorszewska. A review of the cacna gene family: its role in neurological disorders. Diseases, 12:90, May 2024. URL: https://doi.org/10.3390/diseases12050090, doi:10.3390/diseases12050090. This article has 53 citations.
(fox2024developingapathway pages 1-2): Pangkong M. Fox, Sunitha Malepati, Lisa Manaster, Elsa Rossignol, and Jeffrey L. Noebels. Developing a pathway to clinical trials for cacna1a-related epilepsies: a patient organization perspective. Therapeutic Advances in Rare Disease, Jan 2024. URL: https://doi.org/10.1177/26330040241245725, doi:10.1177/26330040241245725. This article has 10 citations.
(kessi2023thegenotype–phenotypecorrelations pages 1-2): Miriam Kessi, Baiyu Chen, Nan Pang, Lifen Yang, Jing Peng, Fang He, and Fei Yin. The genotype–phenotype correlations of the cacna1a-related neurodevelopmental disorders: a small case series and literature reviews. Frontiers in Molecular Neuroscience, Jul 2023. URL: https://doi.org/10.3389/fnmol.2023.1222321, doi:10.3389/fnmol.2023.1222321. This article has 23 citations.
(szymanowicz2024areviewof pages 3-4): Oliwia Szymanowicz, Artur Drużdż, Bartosz Słowikowski, Sandra Pawlak, Ewelina Potocka, Ulyana Goutor, Mateusz Konieczny, Małgorzata Ciastoń, Aleksandra Lewandowska, Paweł P. Jagodziński, Wojciech Kozubski, and Jolanta Dorszewska. A review of the cacna gene family: its role in neurological disorders. Diseases, 12:90, May 2024. URL: https://doi.org/10.3390/diseases12050090, doi:10.3390/diseases12050090. This article has 53 citations.
(fox2024developingapathway pages 2-3): Pangkong M. Fox, Sunitha Malepati, Lisa Manaster, Elsa Rossignol, and Jeffrey L. Noebels. Developing a pathway to clinical trials for cacna1a-related epilepsies: a patient organization perspective. Therapeutic Advances in Rare Disease, Jan 2024. URL: https://doi.org/10.1177/26330040241245725, doi:10.1177/26330040241245725. This article has 10 citations.
(szymanowicz2024areviewof pages 11-12): Oliwia Szymanowicz, Artur Drużdż, Bartosz Słowikowski, Sandra Pawlak, Ewelina Potocka, Ulyana Goutor, Mateusz Konieczny, Małgorzata Ciastoń, Aleksandra Lewandowska, Paweł P. Jagodziński, Wojciech Kozubski, and Jolanta Dorszewska. A review of the cacna gene family: its role in neurological disorders. Diseases, 12:90, May 2024. URL: https://doi.org/10.3390/diseases12050090, doi:10.3390/diseases12050090. This article has 53 citations.
(fox2024developingapathway pages 3-5): Pangkong M. Fox, Sunitha Malepati, Lisa Manaster, Elsa Rossignol, and Jeffrey L. Noebels. Developing a pathway to clinical trials for cacna1a-related epilepsies: a patient organization perspective. Therapeutic Advances in Rare Disease, Jan 2024. URL: https://doi.org/10.1177/26330040241245725, doi:10.1177/26330040241245725. This article has 10 citations.
(leung2024mitochondrialdamageand pages 1-2): Tsz Chui Sophia Leung, Eviatar Fields, Namrata Rana, Ru Yi Louisa Shen, Alexandra E. Bernstein, Anna A. Cook, Daniel E. Phillips, and Alanna J. Watt. Mitochondrial damage and impaired mitophagy contribute to disease progression in sca6. Acta Neuropathologica, Jan 2024. URL: https://doi.org/10.1007/s00401-023-02680-z, doi:10.1007/s00401-023-02680-z. This article has 20 citations and is from a highest quality peer-reviewed journal.
(leung2024mitochondrialdamageand pages 5-8): Tsz Chui Sophia Leung, Eviatar Fields, Namrata Rana, Ru Yi Louisa Shen, Alexandra E. Bernstein, Anna A. Cook, Daniel E. Phillips, and Alanna J. Watt. Mitochondrial damage and impaired mitophagy contribute to disease progression in sca6. Acta Neuropathologica, Jan 2024. URL: https://doi.org/10.1007/s00401-023-02680-z, doi:10.1007/s00401-023-02680-z. This article has 20 citations and is from a highest quality peer-reviewed journal.
(szymanowicz2024areviewof pages 15-16): Oliwia Szymanowicz, Artur Drużdż, Bartosz Słowikowski, Sandra Pawlak, Ewelina Potocka, Ulyana Goutor, Mateusz Konieczny, Małgorzata Ciastoń, Aleksandra Lewandowska, Paweł P. Jagodziński, Wojciech Kozubski, and Jolanta Dorszewska. A review of the cacna gene family: its role in neurological disorders. Diseases, 12:90, May 2024. URL: https://doi.org/10.3390/diseases12050090, doi:10.3390/diseases12050090. This article has 53 citations.
(muth2021fampridineandacetazolamide pages 1-2): Carolin Muth, Julian Teufel, Ludger Schöls, Matthis Synofzik, Christiana Franke, Dagmar Timmann, Ulrich Mansmann, and Michael Strupp. Fampridine and acetazolamide in ea2 and related familial ea. Neurology Clinical Practice, Aug 2021. URL: https://doi.org/10.1212/cpj.0000000000001017, doi:10.1212/cpj.0000000000001017. This article has 52 citations.
(indelicato2024naturalhistoryof pages 1-2): Elisabetta Indelicato, Wolfgang Nachbauer, Matthias S. Amprosi, Sarah Maier, Iris Unterberger, Margarete Delazer, Katharina Kaltseis, Stefan Kiechl, Gregor Broessner, Matthias Baumann, and Sylvia Boesch. Natural history of non-polyglutamine cacna1a disease in austria. Journal of Neurology, 271:6618-6627, Aug 2024. URL: https://doi.org/10.1007/s00415-024-12602-y, doi:10.1007/s00415-024-12602-y. This article has 7 citations and is from a domain leading peer-reviewed journal.
(indelicato2024naturalhistoryof pages 2-4): Elisabetta Indelicato, Wolfgang Nachbauer, Matthias S. Amprosi, Sarah Maier, Iris Unterberger, Margarete Delazer, Katharina Kaltseis, Stefan Kiechl, Gregor Broessner, Matthias Baumann, and Sylvia Boesch. Natural history of non-polyglutamine cacna1a disease in austria. Journal of Neurology, 271:6618-6627, Aug 2024. URL: https://doi.org/10.1007/s00415-024-12602-y, doi:10.1007/s00415-024-12602-y. This article has 7 citations and is from a domain leading peer-reviewed journal.
(fox2024developingapathway pages 5-7): Pangkong M. Fox, Sunitha Malepati, Lisa Manaster, Elsa Rossignol, and Jeffrey L. Noebels. Developing a pathway to clinical trials for cacna1a-related epilepsies: a patient organization perspective. Therapeutic Advances in Rare Disease, Jan 2024. URL: https://doi.org/10.1177/26330040241245725, doi:10.1177/26330040241245725. This article has 10 citations.
(indelicato2024naturalhistoryof media 9fb4e801): Elisabetta Indelicato, Wolfgang Nachbauer, Matthias S. Amprosi, Sarah Maier, Iris Unterberger, Margarete Delazer, Katharina Kaltseis, Stefan Kiechl, Gregor Broessner, Matthias Baumann, and Sylvia Boesch. Natural history of non-polyglutamine cacna1a disease in austria. Journal of Neurology, 271:6618-6627, Aug 2024. URL: https://doi.org/10.1007/s00415-024-12602-y, doi:10.1007/s00415-024-12602-y. This article has 7 citations and is from a domain leading peer-reviewed journal.
(indelicato2024naturalhistoryof media 5d2f1b14): Elisabetta Indelicato, Wolfgang Nachbauer, Matthias S. Amprosi, Sarah Maier, Iris Unterberger, Margarete Delazer, Katharina Kaltseis, Stefan Kiechl, Gregor Broessner, Matthias Baumann, and Sylvia Boesch. Natural history of non-polyglutamine cacna1a disease in austria. Journal of Neurology, 271:6618-6627, Aug 2024. URL: https://doi.org/10.1007/s00415-024-12602-y, doi:10.1007/s00415-024-12602-y. This article has 7 citations and is from a domain leading peer-reviewed journal.
(indelicato2024naturalhistoryof media cc87ae80): Elisabetta Indelicato, Wolfgang Nachbauer, Matthias S. Amprosi, Sarah Maier, Iris Unterberger, Margarete Delazer, Katharina Kaltseis, Stefan Kiechl, Gregor Broessner, Matthias Baumann, and Sylvia Boesch. Natural history of non-polyglutamine cacna1a disease in austria. Journal of Neurology, 271:6618-6627, Aug 2024. URL: https://doi.org/10.1007/s00415-024-12602-y, doi:10.1007/s00415-024-12602-y. This article has 7 citations and is from a domain leading peer-reviewed journal.
(schaare2023concomitantcalciumchannelopathies pages 2-3): Donna Schaare, Sara M. Sarasua, Laina Lusk, Shridhar Parthasarathy, Liangjiang Wang, Ingo Helbig, and Luigi Boccuto. Concomitant calcium channelopathies involving cacna1a and cacna1f: a case report and review of the literature. Genes, 14:400, Feb 2023. URL: https://doi.org/10.3390/genes14020400, doi:10.3390/genes14020400. This article has 5 citations.
(leung2024pathologicalchangesin pages 32-36): TCS Leung. Pathological changes in the cerebellum of spinocerebellar ataxia type 6 (sca6): disease progression and selective vulnerability. Unknown journal, 2024.
(leung2024pathologicalchangesin pages 49-53): TCS Leung. Pathological changes in the cerebellum of spinocerebellar ataxia type 6 (sca6): disease progression and selective vulnerability. Unknown journal, 2024.

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Subtypes

Pathophysiology

Pathograph

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Treatments

Source YAML

References & Deep Research

References

Deep Research

Disease Pathophysiology Research Template

Target Disease

Research Objectives

Required Information

1. Core Pathophysiology

2. Key Molecular Players

3. Biological Processes (for GO annotation)

4. Cellular Components

5. Disease Progression

6. Phenotypic Manifestations

Citation Requirements

Output Format

Comprehensive Research Report: Pathophysiology of CACNA1A-Related Disorder (Mendelian)

Scope and nomenclature

1) Core pathophysiology (molecular → cellular → systems)

1.1 Presynaptic calcium entry and synaptic transmission dysfunction

1.2 Gain-of-function (GOF) vs loss-of-function (LOF) as a central organizing principle

1.3 Migraine pathophysiology: cortical spreading depression (CSD)

1.4 Epilepsy/DEE pathophysiology: thalamocortical and inhibitory circuit failure

1.5 SCA6 degeneration and organelle stress: mitochondria and impaired mitophagy as progression modifiers

2) Key molecular players, pathways, cell types, and anatomy

2.1 Genes/proteins (HGNC/UniProt-style annotations)

2.2 Dysregulated molecular pathways / cellular processes (GO-oriented)

2.3 Cell types (CL-oriented)

2.4 Anatomical locations (UBERON-oriented)

2.5 Chemical entities (CHEBI-oriented; clinically relevant)

3) Cellular components (subcellular localization)

4) Disease progression model (sequence of events)

5) Phenotypic manifestations (HP-oriented), linked to mechanisms

6) Recent developments (2023–2024) and “latest research” highlights

6.1 Precision phenotyping and genotype–phenotype correlations

6.2 Trial-readiness infrastructure (real-world implementation of translational pipelines)

6.3 Mechanistic progression biology in SCA6

7) Current applications and real-world implementations

7.1 Symptom-targeted pharmacotherapy (implemented clinically)

7.2 Diagnostics and monitoring

8) Relevant statistics and data (recent cohorts)

8.1 2024 Austrian non-polyQ CACNA1A natural history cohort

8.2 2023 systematic aggregation for CACNA1A-related neurodevelopmental phenotypes

9) Expert opinions and analysis (authoritative perspectives)

Knowledge-base-ready structured annotations

A) Pathophysiology description (narrative)

B) Gene/protein annotations (example GO mappings; names provided for GO curation)

C) Cell type involvement (CL term suggestions)

D) Anatomical locations (UBERON term suggestions)

E) Chemical entities (CHEBI term suggestions)

F) Evidence items (with identifiers present in retrieved sources)

Summary table (mechanism-centric)

Visual evidence (recent cohort phenotype frequencies)