Pediatric Acute-onset Neuropsychiatric Syndromes (PANS / PANDAS)

name: Pediatric Acute-onset Neuropsychiatric Syndromes
display_name: Pediatric Acute-onset Neuropsychiatric Syndromes (PANS / PANDAS)
creation_date: "2026-07-25T00:00:00Z"
description: >-
  A curated grouping of the pediatric acute-onset neuropsychiatric syndrome
  (PANS) umbrella entry and its streptococcus-triggered subset PANDAS. Members
  share the abrupt, dramatic onset of obsessive-compulsive symptoms and/or
  severely restricted food intake with concurrent neuropsychiatric symptoms in
  children, and a proposed post-infectious/immune-mediated basal ganglia
  neuroinflammatory mechanism. PANS is the trigger-agnostic umbrella defined by
  the acute neuropsychiatric phenotype; PANDAS is the subset in which group A
  streptococcal infection is the identified precipitant, mirroring the MONDO
  is-a relationship PANDAS ⊂ PANS.
grouping_basis:
- SHARED_MECHANISM
- SHARED_PHENOTYPE
- CLINICAL_CONVENTION
grouping_rationale: >-
  Grouped as an explicit curated union of the current dismech PANS and PANDAS
  Disease entries, which share an acute-onset childhood neuropsychiatric
  phenotype (abrupt OCD and/or restricted eating plus concurrent
  neuropsychiatric symptoms) and a proposed post-infectious immune-mediated
  basal ganglia mechanism. The shared boundary is clinically-defined
  acute-onset pediatric neuropsychiatric illness of suspected immune origin.
  PANS is retained as the trigger-agnostic umbrella and PANDAS as its
  streptococcus-defined subset rather than lumping them into a single entry,
  because they carry distinct diagnostic criteria (PANDAS additionally requires
  a temporal streptococcal association and prepubertal onset). Related entities
  such as Sydenham chorea and PANDAS-like presentations with other identified
  triggers (e.g., PANS following Mycoplasma) are not listed unless a standalone
  Disease entry is explicitly curated.
mappings:
  mondo_mappings:
  - term:
      id: MONDO:1060178
      label: pediatric acute-onset neuropsychiatric syndrome
    mapping_predicate: skos:closeMatch
    mapping_source: MONDO
    mapping_justification: >-
      closeMatch: the grouping corresponds to the MONDO pediatric acute-onset
      neuropsychiatric syndrome class and its PANDAS subclass, but is
      implemented as an explicit curated union of the current dismech PANS and
      PANDAS Disease entries rather than as an automatic MONDO subtree closure.
    consistency:
    - reference: MONDO
      consistent: CONSISTENT
      notes: >-
        MONDO models PANDAS (MONDO:0019020) as a direct subclass of pediatric
        acute-onset neuropsychiatric syndrome (MONDO:1060178). Listed members
        are the current KB PANS and PANDAS entries; additional subtypes should
        be added only when standalone Disease entries are curated.
membership_criteria:
- description: >-
    A member is a childhood-onset neuropsychiatric disorder defined by the
    abrupt, dramatic onset of obsessive-compulsive symptoms and/or severely
    restricted food intake, with at least one additional concurrent
    neuropsychiatric manifestation, and a proposed post-infectious or
    immune-mediated basis.
  criteria_semantics: NECESSARY
  logic:
    operator: AND
    operands:
    - operator: OR
      description: >-
        A cardinal presenting feature: abrupt obsessive-compulsive symptoms,
        severely restricted food intake, or tics.
      operands:
      - criterion_predicate: HAS_PHENOTYPE
        description: Acute-onset obsessive-compulsive behavior.
        phenotype_term:
          preferred_term: Compulsive behaviors
          term:
            id: HP:0000722
            label: Compulsive behaviors
      - criterion_predicate: HAS_PHENOTYPE
        description: Severely restricted food intake.
        phenotype_term:
          preferred_term: Restrictive eating
          term:
            id: HP:0020302
            label: Restrictive eating
      - criterion_predicate: HAS_PHENOTYPE
        description: Tics.
        phenotype_term:
          preferred_term: Tics
          term:
            id: HP:0100033
            label: Tics
    - operator: OR
      description: >-
        At least one concurrent neuropsychiatric manifestation alongside the
        cardinal feature, as both entries' diagnostic criteria require.
      operands:
      - criterion_predicate: HAS_PHENOTYPE
        description: Anxiety.
        phenotype_term:
          preferred_term: Anxiety
          term:
            id: HP:0000739
            label: Anxiety
      - criterion_predicate: HAS_PHENOTYPE
        description: Emotional lability.
        phenotype_term:
          preferred_term: Emotional lability
          term:
            id: HP:0000712
            label: Emotional lability
members:
- member: Pediatric Acute-onset Neuropsychiatric Syndrome
  member_type: DISEASE
  differentiating_mechanisms:
  - description: >-
      Trigger-agnostic umbrella entry: abrupt-onset OCD or restricted food
      intake plus concurrent neuropsychiatric symptoms attributed to a
      post-infectious/immune-mediated basal ganglia process, without requiring a
      demonstrated streptococcal precipitant. Encompasses cases following
      non-streptococcal infections or non-infectious immune activation.
- member: Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections
  member_type: DISEASE
  differentiating_mechanisms:
  - description: >-
      Streptococcus-defined subset: prepubertal-onset OCD and/or tic disorder
      with an abrupt or episodic relapsing-remitting course temporally
      associated with group A streptococcal infection, attributed to
      post-streptococcal molecular mimicry with anti-basal-ganglia antibodies
      and CaMKII activation. Distinguished from the umbrella by the required
      streptococcal trigger, prepubertal onset, and choreiform movements shared
      with Sydenham chorea.
notes: >-
  The membership logic is an AND of two OR branches, matching the criteria
  `description`: one cardinal presenting feature (abrupt obsessive-compulsive
  symptoms, restrictive eating, or tics) plus at least one concurrent
  neuropsychiatric manifestation. It was previously a bare three-way phenotype
  OR, which was weaker than the text above it claimed. The "post-infectious or
  immune-mediated basis" clause of that description is deliberately not encoded:
  neither entry carries an annotation a `HAS_*` leaf could test for it, and
  inventing one would make the criterion unfalsifiable rather than necessary.

  The restrictive-eating leaf binds `HP:0020302`, not `HP:0002039` Anorexia,
  mirroring the correction in the PANS entry - HPO defines Anorexia as loss of
  appetite, and the PANS cardinal feature is intentional fear-driven
  restriction.

  Exclude Sydenham chorea, isolated tic disorders (e.g., Tourette syndrome),
  primary obsessive-compulsive disorder, and PANDAS-like presentations with
  other identified triggers unless a standalone Disease entry is explicitly
  curated as a member.