Benign Familial Infantile Epilepsy

Mendelian MONDO:0017615 Pathograph 6 Epilepsy

Benign familial infantile epilepsy (BFIE) is an autosomal dominant, self-limited epilepsy syndrome of infancy. Affected infants typically present with clusters of focal-onset seizures, with or without secondary generalization, between roughly 3 and 12 months of age. Interictal examination, development, neurological status, and EEG are characteristically normal, and seizures remit spontaneously, usually by the end of the second year. The most frequent molecular cause is heterozygous loss-of-function variants in PRRT2 on chromosome 16, which is allelic to paroxysmal kinesigenic dyskinesia (PKD) and the combined infantile convulsions and choreoathetosis (ICCA) syndrome. A minority of families harbor variants in SCN2A or SCN8A, the latter often presenting as benign familial neonatal-infantile seizures.

Ask OpenScientist

Ask a research question about Benign Familial Infantile Epilepsy. OpenScientist will conduct autonomous deep research using the Disorder Mechanisms Knowledge Base and PubMed literature (typically 10-30 minutes).

Submitting...

Do not include personal health information in your question. Questions and results are cached in your browser's local storage.

1
Inheritance
2
Pathophys.
2
Phenotypes
6
Pathograph
3
Genes
1
Treatments
4
Subtypes
1
Deep Research
👪

Inheritance

1
Autosomal dominant HP:0000006
BFIE is inherited in an autosomal dominant pattern with high but not complete penetrance. PRRT2, SCN2A, and SCN8A variants segregate vertically across multiple generations in reported pedigrees.
Autosomal dominant inheritance
Show evidence (1 reference)
PMID:22243967 SUPPORT Human Clinical
"Benign familial infantile epilepsy (BFIE) is a self-limited seizure disorder that occurs in infancy and has autosomal-dominant inheritance."
The PRRT2 discovery paper explicitly defines BFIE as an autosomal-dominant infantile seizure disorder.
◆

Subtypes

4
PRRT2-related BFIE MONDO:0011593
The most frequent molecular subtype, accounting for >80% of BFIE families. Caused by heterozygous truncating PRRT2 variants leading to haploinsufficiency. Families may also include relatives with paroxysmal kinesigenic dyskinesia or infantile convulsions with choreoathetosis (ICCA).
Infantile Convulsions with Choreoathetosis MONDO:0011178
Combined familial syndrome in which infantile seizures (BFIE) and an adolescent-onset movement disorder (paroxysmal kinesigenic choreoathetosis) co-occur in the same individual or within the same family. Caused by PRRT2 variants, with very high mutation detection rates (>90%).
SCN2A-related Benign Familial Neonatal-Infantile Seizures MONDO:0011904
Clinically intermediate variant in which seizure onset spans the late neonatal period through early infancy. Caused by heterozygous SCN2A missense variants encoding the Nav1.2 voltage-gated sodium channel alpha subunit.
SCN8A-related Benign Familial Infantile Seizures MONDO:0014903
Rarer subtype caused by likely-pathogenic SCN8A variants, with seizure onset in infancy. SCN8A also causes severe developmental and epileptic encephalopathy; benign familial presentations represent the mild end of the SCN8A phenotypic spectrum.
⚙

Pathophysiology

2
PRRT2 Loss-of-Function and Impaired Synaptic Vesicle Release
PRRT2 encodes a presynaptic, transmembrane-anchored protein that interacts with SNAP-25 and synaptotagmin 1/2 and contributes to the calcium-dependent neurotransmitter release machinery. Heterozygous truncating PRRT2 variants cause haploinsufficiency in presynaptic terminals, impairing synchronous neurotransmitter release and altering cortical and basal-ganglia network excitability. This presynaptic defect is the leading mechanistic model for the shared pathogenesis of BFIE, ICCA, and PKD.
neuron link
PRRT2 link
neurotransmitter secretion link ↓ DECREASED synaptic vesicle exocytosis link ↓ DECREASED
brain link cerebral cortex link striatum link
Downstream
Focal-Onset Infantile Seizures PRRT2 haploinsufficiency perturbs calcium-dependent synaptic release, shifting cortical excitatory/inhibitory balance and predisposing the developing brain to focal-onset infantile seizures.
Show evidence (4 references)
PMID:23343561 SUPPORT Other
"PRRT2 is a largely uncharacterised protein. It is expressed in the brain and has been demonstrated to interact with SNAP-25, a component of the molecular machinery involved in the release of neurotransmitters at the presynaptic membrane."
Review summarizing prior in vitro biochemical work establishing PRRT2 presynaptic localization and SNAP-25 interaction.
PMID:27052163 SUPPORT In Vitro
"We show that PRRT2 is enriched in presynaptic terminals and that its silencing decreases the number of synapses and increases the number of docked synaptic vesicles at rest."
Direct cellular evidence that PRRT2 loss perturbs synaptic vesicle pools.
PMID:27052163 SUPPORT In Vitro
"PRRT2-silenced neurons exhibit a severe impairment of synchronous release, attributable to a sharp decrease in release probability and Ca(2+) sensitivity and associated with a marked increase of the asynchronous/synchronous release ratio."
Loss of PRRT2 specifically impairs calcium-dependent synchronous neurotransmitter release.
+ 1 more reference
Pleiotropic PRRT2 Effects Across Cortex and Basal Ganglia
PRRT2 mutations exhibit anatomical and temporal pleiotropy: the same haploinsufficient allele produces cortical infantile seizures (BFIE) early in life and basal-ganglia paroxysmal kinesigenic dyskinesia (PKD) later in childhood or adolescence. ICCA represents the co-expression of both phenotypes within an individual or family.
PRRT2 link
cerebral cortex link striatum link
Downstream
Paroxysmal Kinesigenic Dyskinesia PRRT2 loss-of-function produces adolescent-onset paroxysmal kinesigenic dyskinesia in a subset of carriers, defining the ICCA syndrome when combined with infantile seizures.
Show evidence (1 reference)
PMID:22243967 SUPPORT Human Clinical
"PRRT2 mutations elicit pleiotropy in terms of both age of expression (infancy versus later childhood) and anatomical substrate (cortex versus basal ganglia)."
Directly supports the pleiotropy mechanism distinguishing BFIE from PKD within the same gene.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Referential integrity issues (1):
  • Target 'Paroxysmal Kinesigenic Dyskinesia' (from 'Pleiotropic PRRT2 Effects Across Cortex and Basal Ganglia') not found in named elements
Pathograph: causal mechanism network for Benign Familial Infantile Epilepsy Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
●

Phenotypes

2
Focal-Onset Infantile Seizures Neurological HP:0007359
Show evidence (1 reference)
PMID:22243967 SUPPORT Human Clinical
"Benign familial infantile epilepsy (BFIE) is a self-limited seizure disorder that occurs in infancy and has autosomal-dominant inheritance."
The discovery paper defines BFIE clinically as a self-limited infantile seizure disorder.
Seizure Clusters Neurological HP:0001250
Temporal: RECURRENT
Show evidence (1 reference)
PMID:23077018 SUPPORT Human Clinical
"Benign familial infantile epilepsy (BFIE) is an autosomal dominant epilepsy syndrome characterized by afebrile seizures beginning at about 6 months of age."
Defines BFIE clinically as an autosomal dominant afebrile infantile-seizure syndrome.
🧬

Genetic Associations

3
PRRT2 (Causal loss-of-function variant)
Show evidence (3 references)
PMID:22243967 SUPPORT Human Clinical
"We have identified heterozygous mutations in PRRT2, which encodes proline-rich transmembrane protein 2, in 14 of 17 families (82%) affected by BFIE, indicating that PRRT2 mutations are the most frequent cause of this disorder."
This is the discovery paper establishing PRRT2 as the major BFIE gene.
PMID:23077018 SUPPORT Human Clinical
"PRRT2 mutations are present in >80% of BFIE and >90% ICCA families, but are not a common cause of other forms of infantile epilepsy."
Independent replication of PRRT2 mutation frequency in BFIE and ICCA cohorts.
PMID:23343561 SUPPORT Human Clinical
"The vast majority of these mutations are truncating and are predicted to lead to haploinsufficiency."
Reviews the haploinsufficiency mechanism that unifies PRRT2-related BFIE, ICCA, and PKD.
SCN2A (Causal variant)
Show evidence (1 reference)
PMID:12243921 SUPPORT Human Clinical
"Here, we describe a clinically intermediate variant, benign familial neonatal-infantile seizures, with mutations in the sodium-channel subunit gene SCN2A."
Original identification of SCN2A as the gene underlying benign familial neonatal-infantile seizures.
SCN8A (Causal variant (mild end of SCN8A spectrum))
Show evidence (1 reference)
PMID:38160512 SUPPORT Human Clinical
"Fourteen had a genetic diagnosis (93%): 11 pathogenic; PRRT2 (n=4), KCNQ2 (n=3), SCN2A (n=4), 3 likely pathogenic; KCNQ2 (n=1), SCN8A (n=2)."
Multigenerational Australian SeLFE cohort identifies SCN8A as a contributing gene in self-limited familial neonatal/infantile epilepsy.
💊

Treatments

1
Antiseizure Medication Therapy
Action: anticonvulsant agent therapy MAXO:0000167
Agent: carbamazepine ↗ oxcarbazepine ↗
Short-term antiseizure medication, often with sodium-channel blockers such as carbamazepine or oxcarbazepine, controls infantile seizure clusters in BFIE. Therapy is typically time-limited because seizures remit spontaneously.
Target Phenotypes: Focal-onset seizure ↗
Show evidence (1 reference)
PMID:38160512 PARTIAL Human Clinical
"GDD was associated with older age at last seizure (p=0.03), longer epilepsy duration (p=0.02), and higher number of anti-seizure medications (p=0.05)."
Confirms antiseizure medications are used in management and links treatment burden to developmental outcomes.
{ }

Source YAML

click to show 
name: Benign Familial Infantile Epilepsy
creation_date: "2026-05-13T12:00:00Z"
updated_date: "2026-05-13T18:00:00Z"
category: Mendelian
description: >-
  Benign familial infantile epilepsy (BFIE) is an autosomal dominant,
  self-limited epilepsy syndrome of infancy. Affected infants typically present
  with clusters of focal-onset seizures, with or without secondary
  generalization, between roughly 3 and 12 months of age. Interictal examination,
  development, neurological status, and EEG are characteristically normal, and
  seizures remit spontaneously, usually by the end of the second year. The most
  frequent molecular cause is heterozygous loss-of-function variants in PRRT2 on
  chromosome 16, which is allelic to paroxysmal kinesigenic dyskinesia (PKD) and
  the combined infantile convulsions and choreoathetosis (ICCA) syndrome. A
  minority of families harbor variants in SCN2A or SCN8A, the latter often
  presenting as benign familial neonatal-infantile seizures.
disease_term:
  preferred_term: benign familial infantile epilepsy
  term:
    id: MONDO:0017615
    label: benign familial infantile epilepsy
synonyms:
- BFIE
- benign familial infantile seizures
- BFIS
- self-limited familial infantile epilepsy
parents:
- Epilepsy
has_subtypes:
- name: PRRT2-related BFIE
  subtype_term:
    preferred_term: seizures, benign familial infantile, 2
    term:
      id: MONDO:0011593
      label: seizures, benign familial infantile, 2
  description: >-
    The most frequent molecular subtype, accounting for >80% of BFIE families.
    Caused by heterozygous truncating PRRT2 variants leading to
    haploinsufficiency. Families may also include relatives with paroxysmal
    kinesigenic dyskinesia or infantile convulsions with choreoathetosis (ICCA).
- name: ICCA
  display_name: Infantile Convulsions with Choreoathetosis
  subtype_term:
    preferred_term: infantile convulsions and choreoathetosis
    term:
      id: MONDO:0011178
      label: infantile convulsions and choreoathetosis
  description: >-
    Combined familial syndrome in which infantile seizures (BFIE) and an
    adolescent-onset movement disorder (paroxysmal kinesigenic choreoathetosis)
    co-occur in the same individual or within the same family. Caused by PRRT2
    variants, with very high mutation detection rates (>90%).
- name: SCN2A-related BFNIS
  display_name: SCN2A-related Benign Familial Neonatal-Infantile Seizures
  subtype_term:
    preferred_term: seizures, benign familial infantile, 3
    term:
      id: MONDO:0011904
      label: seizures, benign familial infantile, 3
  description: >-
    Clinically intermediate variant in which seizure onset spans the late
    neonatal period through early infancy. Caused by heterozygous SCN2A missense
    variants encoding the Nav1.2 voltage-gated sodium channel alpha subunit.
- name: SCN8A-related BFIS
  display_name: SCN8A-related Benign Familial Infantile Seizures
  subtype_term:
    preferred_term: seizures, benign familial infantile, 5
    term:
      id: MONDO:0014903
      label: seizures, benign familial infantile, 5
  description: >-
    Rarer subtype caused by likely-pathogenic SCN8A variants, with seizure onset
    in infancy. SCN8A also causes severe developmental and epileptic
    encephalopathy; benign familial presentations represent the mild end of the
    SCN8A phenotypic spectrum.
inheritance:
- name: Autosomal dominant
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >-
    BFIE is inherited in an autosomal dominant pattern with high but not
    complete penetrance. PRRT2, SCN2A, and SCN8A variants segregate vertically
    across multiple generations in reported pedigrees.
  evidence:
  - reference: PMID:22243967
    reference_title: PRRT2 mutations cause benign familial infantile epilepsy and infantile convulsions with choreoathetosis syndrome.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Benign familial infantile epilepsy (BFIE) is a self-limited seizure
      disorder that occurs in infancy and has autosomal-dominant inheritance.
    explanation: The PRRT2 discovery paper explicitly defines BFIE as an autosomal-dominant infantile seizure disorder.
genetic:
- name: PRRT2
  association: Causal loss-of-function variant
  gene_term:
    preferred_term: PRRT2
    term:
      id: hgnc:30500
      label: PRRT2
  notes: >-
    Heterozygous truncating PRRT2 variants are the most common cause of BFIE
    (~80% of families) and ICCA (>90% of families). The recurrent
    c.649dupC/p.R217fsX224 frameshift is the predominant pathogenic allele and
    is predicted to cause haploinsufficiency.
  evidence:
  - reference: PMID:22243967
    reference_title: PRRT2 mutations cause benign familial infantile epilepsy and infantile convulsions with choreoathetosis syndrome.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      We have identified heterozygous mutations in PRRT2, which encodes
      proline-rich transmembrane protein 2, in 14 of 17 families (82%) affected
      by BFIE, indicating that PRRT2 mutations are the most frequent cause of
      this disorder.
    explanation: This is the discovery paper establishing PRRT2 as the major BFIE gene.
  - reference: PMID:23077018
    reference_title: PRRT2 phenotypic spectrum includes sporadic and fever-related infantile seizures.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      PRRT2 mutations are present in >80% of BFIE and >90% ICCA families, but
      are not a common cause of other forms of infantile epilepsy.
    explanation: Independent replication of PRRT2 mutation frequency in BFIE and ICCA cohorts.
  - reference: PMID:23343561
    reference_title: "Role of PRRT2 in common paroxysmal neurological disorders: a gene with remarkable pleiotropy."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The vast majority of these mutations are truncating and are predicted to
      lead to haploinsufficiency.
    explanation: Reviews the haploinsufficiency mechanism that unifies PRRT2-related BFIE, ICCA, and PKD.
- name: SCN2A
  association: Causal variant
  gene_term:
    preferred_term: SCN2A
    term:
      id: hgnc:10588
      label: SCN2A
  notes: >-
    Heterozygous SCN2A missense variants cause benign familial neonatal-infantile
    seizures (BFNIS), a clinically intermediate phenotype with onset spanning
    the late neonatal period into infancy.
  evidence:
  - reference: PMID:12243921
    reference_title: Sodium-channel defects in benign familial neonatal-infantile seizures.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Here, we describe a clinically intermediate variant, benign familial
      neonatal-infantile seizures, with mutations in the sodium-channel subunit
      gene SCN2A.
    explanation: Original identification of SCN2A as the gene underlying benign familial neonatal-infantile seizures.
- name: SCN8A
  association: Causal variant (mild end of SCN8A spectrum)
  gene_term:
    preferred_term: SCN8A
    term:
      id: hgnc:10596
      label: SCN8A
  notes: >-
    SCN8A variants are an uncommon cause of self-limited familial epilepsy of
    neonatal/infantile onset; the same gene more often causes severe SCN8A
    developmental and epileptic encephalopathy.
  evidence:
  - reference: PMID:38160512
    reference_title: Neurodevelopmental outcomes in a cohort of Australian families with self-limited familial epilepsy of neonatal/infantile onset.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Fourteen had a genetic diagnosis (93%): 11 pathogenic; PRRT2 (n=4), KCNQ2
      (n=3), SCN2A (n=4), 3 likely pathogenic; KCNQ2 (n=1), SCN8A (n=2).
    explanation: Multigenerational Australian SeLFE cohort identifies SCN8A as a contributing gene in self-limited familial neonatal/infantile epilepsy.
pathophysiology:
- name: PRRT2 Loss-of-Function and Impaired Synaptic Vesicle Release
  description: >-
    PRRT2 encodes a presynaptic, transmembrane-anchored protein that interacts
    with SNAP-25 and synaptotagmin 1/2 and contributes to the
    calcium-dependent neurotransmitter release machinery. Heterozygous
    truncating PRRT2 variants cause haploinsufficiency in presynaptic terminals,
    impairing synchronous neurotransmitter release and altering cortical and
    basal-ganglia network excitability. This presynaptic defect is the leading
    mechanistic model for the shared pathogenesis of BFIE, ICCA, and PKD.
  role: central_effector
  genes:
  - preferred_term: PRRT2
    term:
      id: hgnc:30500
      label: PRRT2
  cell_types:
  - preferred_term: neuron
    term:
      id: CL:0000540
      label: neuron
  biological_processes:
  - preferred_term: neurotransmitter secretion
    modifier: DECREASED
    term:
      id: GO:0007269
      label: neurotransmitter secretion
  - preferred_term: synaptic vesicle exocytosis
    modifier: DECREASED
    term:
      id: GO:0016079
      label: synaptic vesicle exocytosis
  locations:
  - preferred_term: brain
    term:
      id: UBERON:0000955
      label: brain
  - preferred_term: cerebral cortex
    term:
      id: UBERON:0000956
      label: cerebral cortex
  - preferred_term: striatum
    term:
      id: UBERON:0002435
      label: striatum
  evidence:
  - reference: PMID:23343561
    reference_title: "Role of PRRT2 in common paroxysmal neurological disorders: a gene with remarkable pleiotropy."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      PRRT2 is a largely uncharacterised protein. It is expressed in the brain
      and has been demonstrated to interact with SNAP-25, a component of the
      molecular machinery involved in the release of neurotransmitters at the
      presynaptic membrane.
    explanation: Review summarizing prior in vitro biochemical work establishing PRRT2 presynaptic localization and SNAP-25 interaction.
  - reference: PMID:27052163
    reference_title: PRRT2 Is a Key Component of the Ca(2+)-Dependent Neurotransmitter Release Machinery.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      We show that PRRT2 is enriched in presynaptic terminals and that its
      silencing decreases the number of synapses and increases the number of
      docked synaptic vesicles at rest.
    explanation: Direct cellular evidence that PRRT2 loss perturbs synaptic vesicle pools.
  - reference: PMID:27052163
    reference_title: PRRT2 Is a Key Component of the Ca(2+)-Dependent Neurotransmitter Release Machinery.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      PRRT2-silenced neurons exhibit a severe impairment of synchronous release,
      attributable to a sharp decrease in release probability and Ca(2+)
      sensitivity and associated with a marked increase of the
      asynchronous/synchronous release ratio.
    explanation: Loss of PRRT2 specifically impairs calcium-dependent synchronous neurotransmitter release.
  - reference: PMID:27052163
    reference_title: PRRT2 Is a Key Component of the Ca(2+)-Dependent Neurotransmitter Release Machinery.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      PRRT2 interacts with the synaptic proteins SNAP-25 and synaptotagmin 1/2.
    explanation: Defines the molecular interactions placing PRRT2 in the SNARE/Ca2+-sensing release machinery.
  downstream:
  - target: Focal-Onset Infantile Seizures
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - presynaptic neurotransmitter release imbalance
    - cortical network hyperexcitability
    description: >-
      PRRT2 haploinsufficiency perturbs calcium-dependent synaptic release,
      shifting cortical excitatory/inhibitory balance and predisposing the
      developing brain to focal-onset infantile seizures.
    evidence:
    - reference: PMID:27052163
      reference_title: PRRT2 Is a Key Component of the Ca(2+)-Dependent Neurotransmitter Release Machinery.
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: >-
        Heterozygous mutations in proline-rich transmembrane protein 2 (PRRT2)
        underlie a group of paroxysmal disorders, including epilepsy,
        kinesigenic dyskinesia, and migraine.
      explanation: Links PRRT2 loss-of-function to the paroxysmal epilepsy phenotype that defines BFIE.
- name: Pleiotropic PRRT2 Effects Across Cortex and Basal Ganglia
  description: >-
    PRRT2 mutations exhibit anatomical and temporal pleiotropy: the same
    haploinsufficient allele produces cortical infantile seizures (BFIE) early
    in life and basal-ganglia paroxysmal kinesigenic dyskinesia (PKD) later in
    childhood or adolescence. ICCA represents the co-expression of both
    phenotypes within an individual or family.
  role: pleiotropy_mechanism
  genes:
  - preferred_term: PRRT2
    term:
      id: hgnc:30500
      label: PRRT2
  locations:
  - preferred_term: cerebral cortex
    term:
      id: UBERON:0000956
      label: cerebral cortex
  - preferred_term: striatum
    term:
      id: UBERON:0002435
      label: striatum
  evidence:
  - reference: PMID:22243967
    reference_title: PRRT2 mutations cause benign familial infantile epilepsy and infantile convulsions with choreoathetosis syndrome.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      PRRT2 mutations elicit pleiotropy in terms of both age of expression
      (infancy versus later childhood) and anatomical substrate (cortex versus
      basal ganglia).
    explanation: Directly supports the pleiotropy mechanism distinguishing BFIE from PKD within the same gene.
  downstream:
  - target: Paroxysmal Kinesigenic Dyskinesia
    causal_link_type: DIRECT
    description: PRRT2 loss-of-function produces adolescent-onset paroxysmal kinesigenic dyskinesia in a subset of carriers, defining the ICCA syndrome when combined with infantile seizures.
    evidence:
    - reference: PMID:22243967
      reference_title: PRRT2 mutations cause benign familial infantile epilepsy and infantile convulsions with choreoathetosis syndrome.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: >-
        We also report PRRT2 mutations in five of six (83%) families affected by
        infantile convulsions and choreoathetosis (ICCA) syndrome, a familial
        syndrome in which infantile seizures and an adolescent-onset movement
        disorder, paroxysmal kinesigenic choreoathetosis (PKC), co-occur.
      explanation: Directly supports PRRT2-mediated PKD/PKC as the downstream movement-disorder phenotype in ICCA families.
phenotypes:
- name: Focal-Onset Infantile Seizures
  category: Neurological
  diagnostic: true
  description: >-
    Affected infants present with brief focal-onset seizures, often clustered,
    sometimes with secondary bilateral spread to tonic-clonic activity. Onset is
    typically between 3 and 12 months of age, on a background of normal
    development, neurological examination, and interictal EEG.
  phenotype_term:
    preferred_term: Focal-onset seizure
    term:
      id: HP:0007359
      label: Focal-onset seizure
  evidence:
  - reference: PMID:22243967
    reference_title: PRRT2 mutations cause benign familial infantile epilepsy and infantile convulsions with choreoathetosis syndrome.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Benign familial infantile epilepsy (BFIE) is a self-limited seizure
      disorder that occurs in infancy and has autosomal-dominant inheritance.
    explanation: The discovery paper defines BFIE clinically as a self-limited infantile seizure disorder.
- name: Seizure Clusters
  category: Neurological
  description: >-
    Seizures typically occur in clusters, with multiple events over hours or
    days, followed by long seizure-free intervals. This temporal pattern is a
    characteristic feature of BFIE.
  phenotype_term:
    preferred_term: Recurrent seizure clusters
    term:
      id: HP:0001250
      label: Seizure
    temporality: RECURRENT
  evidence:
  - reference: PMID:23077018
    reference_title: PRRT2 phenotypic spectrum includes sporadic and fever-related infantile seizures.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Benign familial infantile epilepsy (BFIE) is an autosomal dominant
      epilepsy syndrome characterized by afebrile seizures beginning at about 6
      months of age.
    explanation: Defines BFIE clinically as an autosomal dominant afebrile infantile-seizure syndrome.
progression:
- phase: Seizure clusters in infancy
  age_range: 3-12 months
  notes: >-
    Affected infants present with clusters of focal-onset seizures, often within
    a single day or over several days, on a background of normal development
    and neurological examination. Interictal EEG is characteristically normal.
  evidence:
  - reference: PMID:23077018
    reference_title: PRRT2 phenotypic spectrum includes sporadic and fever-related infantile seizures.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Benign familial infantile epilepsy (BFIE) is an autosomal dominant
      epilepsy syndrome characterized by afebrile seizures beginning at about 6
      months of age.
    explanation: Supports the infantile-onset seizure phase centered on ~6 months.
- phase: Spontaneous remission
  age_range: by second year
  notes: >-
    Seizures remit spontaneously, typically by the end of the second year, with
    normal long-term development in most individuals. A subset of carriers
    develop adolescent-onset paroxysmal kinesigenic dyskinesia (ICCA phenotype).
  evidence:
  - reference: PMID:38160512
    reference_title: Neurodevelopmental outcomes in a cohort of Australian families with self-limited familial epilepsy of neonatal/infantile onset.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Ten of 50 individuals (20%) had seizure recurrence, aged 8-65 years.
      Median time from last neonatal/infantile seizure was 11.8/12.8 years.
    explanation: Long-term outcome study shows the canonical self-limited course with a small but real risk of later seizure recurrence.
  - reference: PMID:38160512
    reference_title: Neurodevelopmental outcomes in a cohort of Australian families with self-limited familial epilepsy of neonatal/infantile onset.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Paroxysmal kinesiogenic dyskinesia (n=5) occurred in 4 families and
      hemiplegic migraine (n=8) in 3 families.
    explanation: Documents the later-onset PKD and migraine phenotypes that emerge in PRRT2-related BFIE families.
- phase: Long-term outcome
  notes: >-
    Most individuals achieve normal cognitive and adaptive functioning, though
    a minority show mild neurodevelopmental concerns, particularly when seizure
    burden in infancy was high or treatment duration was prolonged.
  evidence:
  - reference: PMID:38160512
    reference_title: Neurodevelopmental outcomes in a cohort of Australian families with self-limited familial epilepsy of neonatal/infantile onset.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Vineland-3 identified 3 had low-average and 3 had mild-moderately impaired
      functioning. The majority (82%) were average.
    explanation: Adaptive function outcomes support generally favorable long-term outcome with a minority showing mild impairment.
treatments:
- name: Antiseizure Medication Therapy
  description: >-
    Short-term antiseizure medication, often with sodium-channel blockers such
    as carbamazepine or oxcarbazepine, controls infantile seizure clusters in
    BFIE. Therapy is typically time-limited because seizures remit
    spontaneously.
  treatment_term:
    preferred_term: anticonvulsant agent therapy
    term:
      id: MAXO:0000167
      label: anticonvulsant agent therapy
    therapeutic_agent:
    - preferred_term: carbamazepine
      term:
        id: CHEBI:3387
        label: carbamazepine
    - preferred_term: oxcarbazepine
      term:
        id: CHEBI:7824
        label: oxcarbazepine
  target_phenotypes:
  - preferred_term: Focal-onset seizure
    term:
      id: HP:0007359
      label: Focal-onset seizure
  evidence:
  - reference: PMID:38160512
    reference_title: Neurodevelopmental outcomes in a cohort of Australian families with self-limited familial epilepsy of neonatal/infantile onset.
    supports: PARTIAL
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      GDD was associated with older age at last seizure (p=0.03), longer
      epilepsy duration (p=0.02), and higher number of anti-seizure medications
      (p=0.05).
    explanation: Confirms antiseizure medications are used in management and links treatment burden to developmental outcomes.
datasets: []
📚

References & Deep Research

Deep Research

1
Benign Familial Infantile Epilepsy Deep Research Fallback ▸

Benign Familial Infantile Epilepsy Deep Research Fallback

Provider Attempts

  • timeout 75s just research-disorder falcon Benign_Familial_Infantile_Epilepsy
  • Result: timed out with Recipe research-disorder was terminated by signal 15.
  • timeout 75s just research-disorder openai Benign_Familial_Infantile_Epilepsy
  • Result: timed out with Recipe research-disorder was terminated by signal 15.

No provider-generated research artifact was available within the bounded window. The YAML therefore was curated directly from MONDO/ORPHA structured records and PubMed abstracts cached via just fetch-reference.

Evidence-backed curation scope

The entry integrates the following deterministic sources:

  • MONDO terms for the disease and its molecular subtypes:
  • MONDO:0017615 benign familial infantile epilepsy (root).
  • MONDO:0011593 seizures, benign familial infantile, 2 (PRRT2-related).
  • MONDO:0011178 infantile convulsions and choreoathetosis (ICCA).
  • MONDO:0011904 seizures, benign familial infantile, 3 (SCN2A-related BFNIS).
  • MONDO:0014903 seizures, benign familial infantile, 5 (SCN8A-related).
  • HGNC gene identifiers: hgnc:30500 PRRT2, hgnc:10588 SCN2A, hgnc:10596 SCN8A.
  • PubMed caches (six PMIDs):
  • PMID:22243967 PRRT2 discovery paper establishing PRRT2 as the major BFIE gene and the shared molecular cause of BFIE and ICCA.
  • PMID:23077018 PRRT2 phenotypic-spectrum cohort confirming PRRT2 mutation frequencies (>80% BFIE, >90% ICCA) and the afebrile, autosomal-dominant infantile-seizure clinical definition.
  • PMID:23343561 review of PRRT2 across paroxysmal neurological disorders, summarising the truncating/haploinsufficiency mutation mechanism and SNAP-25 interaction.
  • PMID:27052163 mechanistic cellular study showing PRRT2 loss impairs Ca2+-dependent synchronous synaptic vesicle release and SNAP-25/synaptotagmin 1/2 interactions.
  • PMID:12243921 original identification of SCN2A as the gene underlying benign familial neonatal-infantile seizures (BFNIS).
  • PMID:38160512 Australian long-term cohort of self-limited familial neonatal/infantile epilepsy reporting genetic yields (PRRT2, KCNQ2, SCN2A, SCN8A), seizure-recurrence rates, late-onset PKD and hemiplegic migraine, antiseizure-medication burden, and Vineland-3 adaptive function outcomes.

Integrated Literature Synthesis

BFIE is an autosomal-dominant, self-limited focal epilepsy of infancy. PMID:22243967 (Heron et al., 2012) established PRRT2 as the dominant gene, identifying heterozygous truncating mutations in 14/17 BFIE families (82%) and in 5/6 ICCA families (83%) and noting the pleiotropy of PRRT2 across age (infancy vs. later childhood) and anatomical substrate (cortex vs. basal ganglia). PMID:23077018 (Ono et al., 2012) independently replicated PRRT2 mutation frequencies (>80% BFIE, >90% ICCA), provided the canonical clinical definition (afebrile autosomal-dominant infantile seizures with onset around 6 months of age), and showed PRRT2 mutations do not extend to other infantile epilepsy syndromes. PMID:23343561 (Ebrahimi-Fakhari et al., 2015) reviews the unifying molecular mechanism: the vast majority of PRRT2 variants are truncating and predicted to cause haploinsufficiency at the presynaptic SNAP-25/SNARE machinery, explaining the shared pathogenesis of BFIE, ICCA, and paroxysmal kinesigenic dyskinesia (PKD). PMID:27052163 (Valente et al., 2016) provides the direct cellular evidence: PRRT2 is enriched at presynaptic terminals, interacts with SNAP-25 and synaptotagmin 1/2, and its loss decreases synapse number, increases docked synaptic vesicles at rest, and severely impairs synchronous Ca2+-dependent neurotransmitter release.

Beyond PRRT2, PMID:12243921 (Heron et al., 2002) identified SCN2A missense variants as the cause of benign familial neonatal-infantile seizures (BFNIS), a clinically intermediate syndrome bridging the neonatal and infantile onset windows. PMID:38160512 (Howell et al., 2024) provides the most comprehensive long-term cohort: 14/15 of their Australian self-limited familial epilepsy families had a genetic diagnosis, with the gene mix PRRT2 (n=4), KCNQ2 (n=3), SCN2A (n=4), and SCN8A (n=2). The same cohort reports that 10/50 individuals had later seizure recurrence (median 11.8-12.8 years after the last infantile seizure), that paroxysmal kinesigenic dyskinesia (5 individuals, 4 families) and hemiplegic migraine (8 individuals, 3 families) emerged later in life, that the majority (82%) of carriers had average Vineland-3 adaptive functioning, and that global developmental delay was associated with older age at last seizure, longer epilepsy duration, and a higher number of antiseizure medications.

Curation Notes

  • The "Seizure Clusters" phenotype uses the generic HP:0001250 (Seizure) with temporality: RECURRENT. The more specific HP:0033349 (Seizure cluster) was considered but is classified under HP:0012823 (Clinical modifier) rather than HP:0000118 (Phenotypic abnormality), so it is not reachable from the PhenotypeTerm enum source nodes. HP:0031796 (Recurrent), the direct parent of HP:0033349, is the meaning of the RECURRENT temporality enum value, so this composition preserves the clinical semantics within the schema.
  • Treatment evidence is intentionally PARTIAL: PMID:38160512 reports ASM burden in this cohort but does not establish first-line agent efficacy. Carbamazepine and oxcarbazepine are captured as therapeutic_agent CHEBI entries based on standard pediatric epilepsy clinical practice for BFIE, while the formal evidence link is anchored to PMID:38160512's documentation of ASM use.
  • KCNQ2-related BFNS was intentionally excluded from has_subtypes because KCNQ2-associated benign familial neonatal seizures are a distinct nosological entity from BFIE proper; PMID:38160512 includes KCNQ2 carriers in its self-limited familial epilepsy cohort but they are not BFIE.